So, I'm 4 day's late for my period, on no BC, had unprotected sex once (ejaculated inside me) a day after my last period. But a used the pull out method a handful of times from last period until now. Just now I noticed thick blood tinged mucus when I wipe. It's only tiny streaks, hardly noticeable, I'm always on time for my period, also I have taken 2 HPT and both negative. Need help in finding out what is the cause, I'm worried :(