Sex after "chemical pregnancy"

I was told I had an ectopic pregnancy but my doctor informed me because my levels fell so fast and steadily they are citing it as a "chemical pregnancy." I stopped bleeding 4 days ago. Anyone have experience with this? When can my husband and I have sex again? My levels went from 1500 to 950 to 375 to 58. Last checked was Tuesday and it was 58.

Thank you!