Pregnant after giving birth..

kentucky_mommy
I gave birth June 21st and I haven't started my period yet, I'll be 7 weeks pp next Tuesday. I've been having light cramping like period cramps, but I've been naesous and puking for 2 weeks now. I've been on my birth control alittle over a week now. How possible is it that I could be pregnant if we messed around before I got on birth control? No negative comments please