I have this happen approx. two times every year, meaning I get my period, then in 15 days I see blood again (small amount) and then in 15 days I get my period again.
I talked to my gyno and he said as long as it is only small amount of blood, it is caused by stress. When I asked him if I can take birthcontrol pills with my Crohns, he said the only reason he forbits it, is because when you have diarrea, the pill is not completely absorbed, meaning that it could lead to possible pregnancy. So I thought it was not worth poisoning my body with b/c pills and still have unwanted pregnancy, so me and hubby chose the old fashioned way: condoms.