Omggg can't do it again.

So I usually have my period for 5 days buuut I had my period JAN 23 an JAN 24,only 2 days.. we had sex on an off my period an he didn't pull out (stupid I know) well then I started my period again lasting for three days (ONLY ) the first,second an third of feb..an again having sex on an off my period. now I still haven't started my period. An i know it's only the third but iv been having white discharge (more then normal) not to mention I JUST had a baby 6 months ago. Wtf is going on. I took a pregnancy test about 4 weeks ago an it said negitive, then about 2 weeks ago i took a nother an it was supposivley a invalid test, I haven't taken another but wtf is going on Could I be pregnant AGAIN??? I'm so scared to go to the doctor an find out. Not to mention I'm not with my baby daddy an iv only been with my current bf for 2 an a half months.. uhm helppp? Suggestions? Something!!