Hi, I am new here and wanted someone's help on getting past plateaus. I don't know if this IS a plateau or not. I started at 172 in Feb. I am 38, 5ft 3.5 inches tall. I changed my diet and started walking. Now I am walking up to 2 miles per day, sometimes 3 if I walk again in the evening. I am down to 158-159. I can't seem to get past this point.

I have been this weight now for 6-8 days. I know the first 10-12 lbs or so was probably just water weight. Have I just hit a spot to where I am starting to lose fat and it's slowing down alot? I started jogging/walking, something a little different. (can only jog for one minute at a time) I eat alot of salads, and for breakfast either kellog's special K, oatmeal, with fruit or boiled egg. I only drink water or unsweet tea. My husband and I split a sub from subway alot. I don't eat any sweets, well I do have an occasional skinny cow icecream.
If I am walking and jogging, am I gaining muscle maybe? and another thing is my cycle will start next week and I am wondering if my body is hanging on a little bit of fluid, I do get a little bloated a week or so before.
I don't want to get discouraged,

but I really have a goal of 155 by the end of this month. Is half a pound or a pound normal to loose over a week? Am I eating enough? I am getting hooked on salads, and I will throw in some grilled chicken for protein.
At first the weight was falling off, now the brakes have been put on, and my body is being hard headed. I don't have a gym membership, right now money is tight, but I do have a treadmill and weights. My ultimate goal weight is 135.
Sorry so long, any help would be appreciated!!!