Someone please help. Idk what this means

I don't want to get pregnant my parents would kill me....and I'm past date on my period.. i am dumb because I do have unprotected sex and I had unprotected sex again lastnight (I don't think he cam In me) . All day I've been having cramps and feeling slightly light headed. I also saw in my underwear really sticky white and stretchy stuff in it and I have no idea what this is or means. Please help me