When I was considering getting the shot, my dr said that he would need to know for sure that I wasn't pregnant. So he did a urine test, and a blood test. It turned out I was pregnant, so I didn't get it.

Unfortunately there's not really much you can do about it now, but my advice is please do not stress over something you had no control over. You'll be having your scan in 2 weeks, so fingers crossed all turns out ok then.
Definitely mention it to your dr as well, hopefully he/she can put your mind as ease a little.

Good luck