No period

i'm currently 10 days late. me and my boyfriend are very careful in bed and he never finishes in the condom since our first pregnancy scare. we had sex in the beginning of march and the condom broke and we ended up having raw sex (not knowing the condom broke) but he never finished inside me. when we found out it was broken i took a plan b less than 24 hours later (this is my 2nd time taking plan b since i last took it 3 months ago) .

when my period was supposed to come i got brown discharge for like 2 days but nothing else. i took a test 6 days after my missed period and got a negative result. i'm super freaked out by this and i don't know what's happening, does anyone know???

i had a yeast infection in the beginning of my last period and was taking antibiotics for it, does that effect my cycle??