Painful ovulation, shorter/lighter periods? Whats going on!?

I'm 26 years old and have had normal periods for years. They always lasted 6 days- being very heavy on the 2nd and 3rd day. About a year and a half ago I started having painful ovulation, but it never effected my periods. The past 3 months or so, my periods have been lighter and shorter lasting only 3-4 days and tapering off after the 2nd day. I do not have heavy bleeding anymore either. The painful ovulation seems to be lasting longer now- about 2 days and seems to happen every month instead of every few months or so. I've also been getting more symptoms of PMS the week before, and cramping during the first day of my period- also not normal for me. I have been ually active and am wondering if this could be producing more hormones and could have anything to do with it? I am in school full time and am more stressed than usual, but would this affect the flow or the cycle? I am still every 28 days like clockwork. And being in school, I can't afford to get checked out until June. Any insight would be greatly appreciated! Thanks!