Am I pregnant???

So I had my period a week ago and my bf and I have been very sexually active. We have not used any protection only the pull out method for as long as we have been together almost 4 or 5 months. Today I noticed some dark dried spotting. I am aware that there is something called implantation bleeding and could mean peegnancy, and we were very aware that pre cum could be a risk. Could I be pregnant. Please has anyone experienced this?