I've had unprotected sex had bleeding but still feel pregnan

Okay so 5 days after my period was done I had sex and the next day if we had sex would have beenmy fertile day so I was def close to it anyway 2 weeks after sex I started getting bad lower back pains it's been 3 weeks and still getting that also in the first week I could never eat and when I smelt food it made me sick to my stumach I could barely eat at night and in the morning I'd feel like I'd have to puke I'd get up and feel very dizzy
And my vision would be messed up I started to get leg cramps and like butt cramps and foot cramps also cramps in my hand it feels like artherites and I'm only 16 just recently I've been getting boob pains randomly just last week I couldn't stop eating and had to pee a lot it looks like I'm getting more pimples and an oily face never had that well I got my period this past week but it wasn't normal I can usually fill a couple tampons a day and a couple pads but not this month I could just wear a pad and be fine I heard some women can bleed durig there pregnancies I'm not on BC used the withdrawl method for the past 6 months also I took a pregnancy test Wednesday night came out negative but still feel prego what do you think I need a lot of answers I'm confused but not worried comment here email me at _[removed]_ I need someone to talk to also I've been tired a lot and just so weak I just wanna lay down