Painful sex at the start

Has anybody had this problem before? My boyfriend and I never had painful sex at the start of our relationship.. for the last couple months, it hurts really bad when he puts it in, and then sometimes also for a couple thrusts and then it’s fine. I thought maybe I’m just not lubricated enough, so we have tried using lube, as well as condoms, and still the same thing.. anyone know what else could be the cause? Its like a sharp shooting pain.. i’ve done the STI testing multiple times as well. I have the occasional itching or discharge, thought maybe I have BV or another yeast infection which is getting checked on Monday, but for the most part I’m usually fine down there until sex.