A woman does not experience morning sickness several days after having sex. It takes much longer for this to occur.
I think you're afraid because this is your first time and you're expecting the worst. Just continue to use condoms properly and you will be fine. You may want to begin using a second method just to ease your mind.
I had the same fears as you when I first had sex. I was sure that I would become pregnant, catch AIDS or contract herpes- or all three! So I would use condoms and spermicide or condoms and the pill.

i agree w/deteragram...i was SO paranoid about having sex the first few times..not even about the sex just the pregnancy issue...we ALWAYS used a condom and he never even went in the condom but I'd still get paranoid...i got on birth control not long after bc I'd have such anxiety about it, my periods were irregular and i never knew if/when it would come and i couldn't take it anymore!