TTC immediately after mc

I had an ectopic pregnancy that ended last Wednesday 💔 Doctor called that my HCG level this Wednesday was 43. (17,000 at time of mc, 700 when I left hospital last Friday). I am DESPERATE to get pregnant again ASAP. Doctor said its best to wait until your second cycle, but I'm tempted to take HPT next week for a BFN then ovulation tests to see when husband and I should BD and try my very first cycle back. 
Does anyone have any experience in this? Any specific reason I should wait for my second cycle? I would be devastated to have another mc but again, I'm extremely anxious to get prego again 🌈