Could it be..

So I haven't missed my period since I had sex back in December. They have been in time. They been a bit weird but heavy to be spotting. I had nausea after my period in January. I had back in pain before my period in February. But now I feel weird. As if there's a bubble in my tummy like fluttering feeling. I do get stabbing pain but thats been going on a week after sex. It's been 12 weeks since I had sex.... Could I be pregnant? Would you still bleed during pregnancy?

Oh and sex hurts.