If it continues heavy it could prevent implantation. It's still very possible, however, so just wait it out to see what happens. I am 47 years, and have had two children. I have always had pretty normal periods, although I was on the pill for 20 years. I have not been on the pill for about 6 years.
Pap smears are normal.
For the last couple years, I have had really bad periods at least every third month. Then, last year, I started having heavy clotting, and pain every month. I never went, but it is really bad now. Your age and with the above history, the most likely cause would be adenomyosis of the uterus. This is endometriosis interna or endometrial glands that go down into the muscle of the uterus.