What do you think?

I had unprotected sex about a month ago and he pulled out, but right after he came he put it back inside me. I know you can get pregnant from pre-cum but I know the chances are low. Couple weeks after I had not been feeling myself. I was throwing up in the mornings and having nausea all day. A couple days before my missed period I took a pregnancy test and they both came out negative. It is now a week after my period should have started and I still haven't gotten it yet. What do you ladies think? Should I test again? Do you think I could be pregnant?