Which weeks in pregnancy to visit gynae?

Hello! As I am going through this pregnancy alone, I would like to be able to save as much as I can, visit as little as possible, and only visit for those important weeks needed because I am a single mother. This is my first pregnancy and I would like to know when is the weeks I need to take note to go visit the gynae. I visited when I was 7 weeks pregnant. I am currently 11 weeks nearly 12 weeks. Please advice and tell me the important weeks I should visit the gynae. Thank you!