Pretty sure I know what will be said about this but worth asking anyway...

I had unprotected sex around 6 weeks ago before my b/c kicked in and I missed my period shortly after (could've been due to the birth control) I had a few negative tests about 4 weeks ago so I stopped thinking I was pregnant but I've since been experiencing spotting, cramps and weight gain. I will be taking another test soon, but my question is could I be??.. 
*edited* I have taken a test and it is definitely negative...my concern now is that I have cysts on my ovaries and I have been informed before that this could cause a false negative? Am i just being paranoid now?