what is this??

vc
So I'm on my 4tg placebo pill today and am having a light brown discharge. On my very first pack of pills, on my last placebo pill I was already off my period. That night that I was on my last placebo pill, I gave my boyfriend head, then about 45 min later we went to my house and he stuck it in once. He didn't cum but I'm worried about left over cum being on his dick when he put it in. My very first month of pills I took perfectly! And later that night I started my first active pill. Should I be fine? And what is this discharge? I'm having very light cramping, but idk if I should test or if my BC is just making my period light