im really scared that i might be pregnant...ive had weird symptoms for the past...i would say 2 to 3 weeks....

3 weeks ago me and my boyfriend had oral sex and he had rubbed up against my genatils a few times...he "stuck it in" i would say about 3 times then i told him to stop....he never ejaculated in me....the day after i was feeling kind of sick but the next day i was fine...i thought nothing of it cause it was my first time and i thought it was normal....for the next week i was fine....but about a week and a half after, out of the blue...i felt like i was going to throw up everywhere and that i had to urinate....then i took a shower and i felt fine. the next day i went to the doctors to get checked for a uti, however they said that my urine had no blood in it and that it was pretty much clear....this put my mind at ease...however a few days later i went to the bathroom and after i had urinated blood started to trickle down....it was light but then when i wiped it looked really dark....i was really scared cause i wasnt due for my period for another week or so and i was also experiencing abdominal pain....so i went to the emergency room and they said that it was a possible uti and they gave me medication for it (which i am still taking)....well this weekend my bleeding stopped after exactly 7 days (a week before i was actually due for my period) but now i feel bloated and like i gained a little weight....if i am pregnant....then i would be 3 weeks???

i know when you get pregnant you can bleed while the fertilized egg is implanted itself in the uterus....but the bleeding is usually light....my bleeding had like blood clots like a heavy period....i know when you have sex to that can bring on an early period....im pretty sure that i dont have a STD....but can someone feel pregnant after 3 weeks? i feel like my stomach is harder like i said before....kind of like im bloated...what do you guys think?