Not sure what to think..

I basically finished my period two weeks ago today. My boyfriend and i are trying to get pregnant, however, this time last week i had 3 days of light bleeding, what i mean by light bleeding is, it was only when i wiped. Wasnt painful, just slight cramping. A few days on now, (5 days) im getting awful sore nipples and a few cramps in my stomach. I do suffer with Strep Group B, which the doctor thinks caused me to miscarriage last year. Not sure what to think, any ideas? Thank youu x