Would love some positive advice

Been trying to conceive for 18 months. Had 2 HSG that show normal, husband sperm is normal with high counts, we just started IUI in September and in October got a positive with HCG numbers of 15, 24, and 39 but numbers went down after a week so I guess Chemical pregnancy 🤷🏽‍♀️ kept doing IUI 2 times after but every time I have to have my cervix dilated with dilators because it’s closed. if we have regular sex it comes right out. My question is since I had 2 normal HSG does that mean sperm can still get through because every time I do IUI they have to open my cervix. We took this month off for IUI and Clomid just to try normal for the New Year. I’m so scared I can get pregnant because of my cervix. Please if anyone knows any tricks or something I would really appreciate it