So . . .
I've had to skip 2 days of exercise from being sick. I've tried to make sure I ate normally during that time, but I knew my appetite was diminished.
Anyway, I was 119 pounds when I went home for fall break (mostly from misjudging my calorie needs) and I freaked my parents out.
I intentionally put 2-3 pounds back on, and I thought I was maintaining just fine. Then somehow, with this whole being sick thing, I lost those pounds and am 119.6 this morning.
I'm not worried about it honestly--but I'm really concerned I'm going to go home for Christmas and see my parents have a conniption over how thin I am.
Furthermore, I've been studying embryology/pregnancy/lactation in my nutrition class, and I'm concerned being so thin might mess with my chances of having children in the future (I haven't had a cycle since July).
Any advice? ? ? ?

as soon as you are feeling better , eat

(Emphasis mine)

This should be a concern, if not a waving red flag. Women skip periods all the time for a lot of reasons, but this should certainly be something you discuss with a doctor. If you're a student, you should be able to go to the student health center for low to no cost and discuss your concerns with at least a nurse-practictioner.

Don't let them dismiss your concerns, either (that's some personal experience talking). I missed my period fo 6 months in college, was told it was stress and put on the pill, then rushed to the ER with a large (thankfully benign) ovarian cyst shortly after that. The two may or may not have been related, but I still feel that if I had been more thoroughly checked out, it wouldn't have happened that way.

One of twelve -

What's your reasoning for dropping down to such a low weight? Are you planning on losing more? Is it easy to maintain at 120, how much do you eat a day?

I have to be honest, my sister is about 5 7 and 120, and I think she looks way to thin. She has hardly any muscle up top, and she just looks very boney and unhealthy to me. Being at 119 right now, you are just slightly underweight for your height according to BMI charts. But the more important question is, can you sustain this weight and eat enough nutrients to nourish your body?

If you aren't getting your period, the answer may be no. But other factors such as stress might be causing that, and not being at such a low weight. You should definately see a Dr. (gynocologist) as soon as you can and have that looked into. I don't want to scare you, but I once went something like 6 months without having a cycle, and I didn't think it was a big deal (I knew I wasn't pregnant) but according to my Dr, when you allow this to happen (depending on the causes) your uterine lining may actually still be building up every month, but the hormones required to cause it to shed (which is what your period is) aren't kicking in, so you have all this gunk building up which can lead to abnormal cell growth (cancer) over time. It wasn't something that he thought anyone should let go on for more than 3 months without knowing the underlying causes and if they need to be treated.

So advice...yes, a low weight can cause fertility issues because you have to have your hormones functioning properly to concieve and you also have to eat enough to sustain a healthy baby. But if you eat a normal amount of calories now and don't have a problem sustaining at 120, then I think you are fine weighing that, assuming it's not causing your cycle to stop.

Oneoftwelve, please read this thread.

I'm not suggesting you are overtraining per se, but it does point to the dangers of skipped periods and what could be going on inside your body.

Do you count your calories? How about upping them some more? You may think you're eating a lot compared to others here, but you are taller than average and young as well. Your caloric needs are simply higher than they are for old ladies like me. :-)

I'm eating at least 1900/day and eating plenty of food (honestly, it feels like a TON of food to me because I eat more vegetarian-ish here at school because the meat is nasty and I don't trust their casserole stuff, so I'm left with cereal, fruit, and sandwiches and salad type stuff--things that you need to eat quite a bit of to reach 2000 calories each day).
I do count calories. In my head I feel like "I can't go over 2000 calories/day--that's for athletes, not people like me."
Maybe my exercising is burning more than I imagine?
I'll definitely gain some over Christmas break--too cold/icy to run and plenty of more calorie-dense foods (more meat and such). I just don't want to drop down at school and gain when I go home all the time--that could form a really bad habit.

I don't think 1900 calories/day is a lot at all for an exercising 5'8' nineteen or twenty year old woman. Maybe buy some nuts and dried fruit to keep in your room? Quick, easy, delicious calories (the fruit is high in its own natural sugar but just make sure you buy the kind with no sugar added).

The average sedentary teen/early 20s girl needs to eat more than you do—and you aren't average. You're 5' 8". You're also not sedentary.

I know it can seem like you are eating a ton when you eat healthy food, but there are ways to make it easier to eat more. I know: I eat as much as 3,200 calories a day, and some days 3,500+. Nuts, peanut butter, avocados, olive oil, etc.: these foods are good for you and high in calories. You can add them to your meals and bump your intake up easily without really increasing the volume of what you are eating. You can also add protein powder to oatmeal and the like.

I realize that you may not be able to cook your own foods or buy protein powder. But does you cafeteria provide you with peanut butter, nuts and the like? Take advantage of the high-calorie, low-volume healthy foods that are available to you.

BTB, meat isn't necessarily calorie dense. Chicken, pork, and ham, for example, are very low in calories. Lean beef can be the same way. I often eat more calories worth of beans than I do of meat.

Thanks for your input!
I'm home now and trying to eat three healthy meals and two healthy snacks a day. I told myself I wouldn't calorie count while here, but it's become almost instinctive. I'm trying to play it by ear and see eating what sorts of things makes me gain/lose/maintain--and I'm trying to incorporate A FEW sweets back into my diet. I'm such a black-and-white person that at school I was just sugar-free completely. Now I'm trying to eat sweets in one-serving increments. We'll see what happens.

At 119 you are underweight, no wonder your parents are concerned. Don't stop counting calories just be sure you are eating wholesome, nutitious foods. Remind your parents that you were sick and that caused you to lose weight but you are trying to get back on track.