Could it be pregnancy symptoms?

A month ago today I had laparoscopic surgery to remove my left Fallopian tube and ectopic pregnancy. My OB told us told wait until I got my first period, and then we could start trying again. My BF is a long haul trucker who came home Sunday and stayed through thanksgiving, and we had sex at least once a day and used the sponge. Today I have heartburn, which I have ONLY ever had in my entire life with my pregnancies (my first resulted in a healthy boy who is now 13 months, the second was ectopic). I am so nervous that I am pregnant again and that it could possibly be another ectopic, or that there may be something bad that happens because I hadn't gotten a period yet and it's too soon. Help/advice/similar tales/good thoughts/happy endings anyone? Thanks so much :-)