When can I expect a period?

I’m going crazy! Had a D&C at 11 weeks on December 6th. Two weeks later we conceived again which ended in a very very early miscarriage. Since then my levels still have not hit zero. However, I think I’m almost there as at my last blood draw I was 18. That was about a week ago I want to say. Now I just have the faintest line on. FRER. You basically wouldn’t be able to tell by a picture if it was an ident or very faint positive. So I know my levels must be getting close to less than 6 or 5. Today I had cramping like I was going to start and I was sooo excited!! Seeing how I haven’t had a period since December 6th and just want my body to get back on track. It’s always rebounded so quickly. Anyway; back to the cramping. I then started to spot a bit and thought this would be it but now the spotting has stopped :(! I’m not sure what to do. Should I just be a bit more patient or should I take the misoprostol the doctor gave me a few weeks back (he told me to take it only if I wanted to). How long after your hcg hit 0 before you got a period?? TIA!