I am a little bit younger than you, but I was diagnosed with UC a couple of years ago. At first I would not get my period or like you, have it very light, but I was on birth control. After over a year after my diagnosis, I was in the hospital and wasnt taking it, and was in remission, when I went back on it, I had a flare up, so I contribituted the flare up to the birth control. Since then, I do get flare ups right before my peroid, no matter what state of remission I am in. They do come closer to every 28 days or longer, when I was younger, or on the pill, they were closer to the 21 days.
I have been able to work while having UC, but had to change location because I need to be closer to the bathroom, and my company was more then will to accomadate. I have called out alot due to the UC and have been hospitalized. It is hard to work and have UC, but as long as I am in remission, its like not having it, I just use the bathroom more often then my fellow employees. I have also had to take leave of absenses a few time and disabilty to get healthy again. As long as you work for a company that can provide you with what you need, you can work.
I agree with not getting dehydrated. I use to get dehydrated all the time, but I have learned that when I am hydrated my symptoms arent as bad, and keep water with me at all times.
I'm so sorry you are going through so much. I'm 48 right now and was diagnosed with UC when I was 22. I didn't have issues with my periods but would encourage you to get checked for ovarian cysts which can cause problems with that. Asacol is fine for pregnant women. I took it all through my pregnancy without any problems. My son was diagnosed with UC when he was 20 but he is in remission due to taking Imuran.
Did your doctor put you on any prednisone to get your flare under control? My UC went in and out of remission over 10 years but got worse over time. I did not have a good doctor monitoring it and there weren't as many treatment options back then. I had emergency surgery to remove my bowel and then had a J-pouch created which has been so successful and as a result am disease free. It is so, so important that you get your flares under control. At the beginning of getting worse you must be in contact with your doctor. The longer active disease goes on in your body the more damage to the lining of your colon goes on. And don't let yourself get dehydrated. It happens so easily with UC.
I worked and went to school throughout my years with UC. It will get better but be vigilant about taking care of yourself and monitoring the disease. Don't be afraid to get treated for depression. It tends to go along with chronic diseases and it is much easier to manage when the depression has been dealt with.