I would talk to you OB about it just to make sure.
years ago I was in a car accident when I lost control of our blazer and flipped it 5 times. I was taken to the hospital and they did a urine pregnancy test, it came back negitive. They sent me in for a ct scan to make sure there wasn't any internal injuries since I wasn't wearing my seatbelt.
Once in there they asked me if I was pregnant. I told them no and that I had just taken a urine pregnancy test. They told me that my uterus was inlarged. I told them I had just had a baby 2 1/2 months ago. They told me to check up with my ob/gyn with in the next week. I was worried then... I went home and took another pregnancy test and it was negitive. Was able to get into the Dr on Wednesday of that week and they did a blood test and I was pregnant, just not far along for a urine test to pick up yet. They said I was about 3 weeks along according to the ultrasound.
The good news in this is I have a very healthy soon to be 12 year old son. None of it harmed him at all, thankfully.
Talk to your Dr about it and hopefully everything turns out ok!