Ok, so I have been in the gym religeously this week, exercising between 30-40 minutes. I am eating healthy foods, not binging, drinking water and so on. The scale has hovered around 229 to 229.5 for a few days.
this morning out of the blue 231!!
What gives?
Is this normal and something to be ignored? Or should I start trying to take a closer look to see if I am still doing something wrong?

Fluctutaions are normal. My weight will vary 2 pounds up or down for no apparent reason.
I don't think you are doing anything wrong, it will go back down again I am sure.

Is it about to be or currently TOM? Did you maybe eat something with a lot of sodium last night? Are you weighing yourself at the same time with the same clothing on?

Those are just a few things I can think of. It's not completely abnormal for the scale to fluctuate. I'm sure people who weigh daily (I've done it and have seen the fluctuations) can chime in. My weight will fluctuate by 2 pounds every day. Whatever I am in the AM, I can count on being 2lbs up right before bedtime.

I personally wouldn't worry about it if you're sticking to your plan - your body will "regulate" itself.

Lots of times your muscles will hold onto water after a particularly hard workout, too. There are lots of reasons your weight can bounce up; it doesn't mean you've gained back two pounds overnight. Daily weighing can be frustrating until you get used to the fluctuations, but it's no reason to give up. You're doing everything right, and as long as you stick to your plan, the weight will continue its downward trend.

Lots of people find it helpful to track their weight daily in a spreadsheet so they can see the overall downward trend in graph form.

Super normal.

For example, I am three pounds heavier this morning than I was yesterday morning.

This time, it is because I had waaaaayyyy too much sodium yesterday. But it can and will also happen for no apparent reason.

When I couldn't stand the fluctuations (despite knowing they are normal) I decided to weigh myself only once a week. It helped a LOT.

OH welcome to the bane of all of our existences!

Lots of water, maybe some green tea if it's fluid retention (works great for me). When I started with my trainer the scale was stuck for a bit, and yes, TOM will affect as well as will sodium consumption or constipation (sorry TMI but true). And that said, some of it is normal.

YES, very normal; it's all a part of the process. That's why it is often recommended to weigh only ONCE A WEEK. The other posters have all mentioned the main reasons for this (TOM, salt/sodium, rigorous exercise, constipation), plus if you are on your legs & feet a lot, that can also cause them to swell and hold water. I have a big issue with that, so I have to put mine up 1-2 times a day.

It should regulate itself out in a few days ...