Ectopic pregnancy

So my husband and I found out that we were pregnant after a miscarriage. I called my doctor and they said they wouldn't see me until after 7 weeks (I had to get a new doc, because I moved to a different city). I told my husband that I wanted to go in before, just for peace of mind. So we go into a clinic and they said that they can do an ultrasound, so we had one and they only saw thickening of the uterus (I was only 4 weeks and a few days then) the next day I started bleeding 😢 we went to the emergency room and we had blood work and an ultrasound, but it was too soon to see anything on an ultrasound. Hcg levels were at 28. Kept getting blood work and ultrasounds until my levels got to 530 and I got another ultrasound and then they noticed a mass and they said it was a confirmed ectopic. They told me to get the injection and so 2 days later we headed to the hospital to get the injection and I had a routine ultrasound and my levels checked and surprisingly they dropped down to 450, so after much discussion with my doctor it seemed like I was having a natural miscarriage, more blood work later Iater that week and my levels were at 460, but my last blood work from Wednesday showed that mr levels were now at 140. So i didn't have the injection, and my doctor said that some women do miscarry ectopics naturally, and that as long as my levels keep going down im good, we will keep testing until they're below 2. Has anyone ever had a natural miscarrying of an ectopic? Oh and she said that it's okay to have sex, as long as we use protection, I thought there might be a risk of infection, but I asked her and she said no, I'm still unsure though.