I am 25 and only during the past 2 yrs have my periods been normal. But in the last 2 months my periods have been strange. They have started out light for the 1st 2 days and then normal. Then this month it was light for about 3 or 4 days and then it really started. I had my period for about 5 days. It really started on a Thursday and was over on a Monday. Then the following Saturday I got it again. Only I noticed I passed 2 blood clots with heavy bleeding then it went to a very light flow. It is still that way now. I think it is over because the pad is clean but there is blood when I go to the bathroom, but not in my urine. It is very light. This is the first time this has happened. My last pap smear was in January and it was normal as was my last exam. I am not a virgin but not sexually active for over 8 yrs and feeling no pain or discomfort.
As I understand, the character of the flow has changed the last two months with spotting and then normal flow and in addition, this month you are actually having extra bleeding that might be characterized as intermenstrual bleeding. These questions are actually some of the most difficult to answer because at this time, we are not sure if it is going to be a chronic, recurrent change or whether this is an isolated one or two cycles that just gets off kilter for reasons we'll never know.
The general rule-of-thumb is to just observe and do nothing unless the menstrual abnormality occurs three cycles in a row. That is because a situation such as you describe happens not infrequently to many women at some time, but does not usually continue as a long term problem. While we don't often know the causes, it is likely that something interfered with normal ovulation during the previous one or two cycles. Sometimes it can be stress or trauma or unusual physical exertion. It may be prescription or over-the-counter medicines taken. Any infections or illnesses could also affect this. If causes such as this don't continue, the menstrual problem will usually straighten out by the third cycle. If it doesn't, you should have an evaluation. Do you think any of these things might apply to your situation?

Yes, some of these may apply to me. During my first abnormal period, I had a cold and was taking Hall's cough drops-4 or 5 a day and Alka-Seltzer Cold Medicine. Then I had taken a sinus sudafed-like medicine from Walmart. The next day I began with the 2nd part to my period. Plus, I have been under stress with exams --3 last week-- and 2 weddings I am in this summer. Thank you for you help.