Doctor, do vaginal infection causes pain during intercourse? It lead to miscarriage? Any problem for next pregnancy?

Yes, no. Yes, vaginal infections can lead to pain with sex. Miscarriages are usually due to unknown factors. Average vaginal infections are unlikely to cause a miscarriage. Next pregnancy will depend on the type of infection. If it is gonorrhea or chlamydia, you could have an increased risk of ectopic pregnancy next time. You should see a doctor and have a pelvic exam.