Am I pregnant?

So I started my period after being almost 2 weeks late. I have had unprotected sex with my boyfriend several times for a few months...he pulled out every time but there's still pre cum. Well anyways I was 2 weeks late and usually have a very heavy period, but it's no heavy at all and is actually very light. I have taken 4 pregnancy tests all of which came up negative but I don't know it's just weird. What do you guys think??