Smoking while trying to conceive

Hello all! I am 25 years old and going to do my first IUI next month! I’m taking prenatal vitamins now completely cut caffeine out of my diet and tryinggggg to eat clean, although I’m a sucker for fast food at times😶 now my question is... i smoke weed or used to at least. My OB/GYN directed me to stop immediately prior to insemination. Does smoking weed while trying to conceive really effect anything? I have two kids already and have been smoking since I was 14😶😶