This may be a weird quest. but Im trying to get preg. & im not, after ejaculation how long do u leave it in u?

I've been"REALLY" trying to get preg. for like 4mnths., but having unprotected w/ my fiance for 9mnths. Also, I've been taking Xanax for the past 6yrs. b/c I have panic attacks & severe anxiety, which means obviously I am always very stressed out which is prob. another reason its not happening....Also I hate to admit this but I have been a long time user of weed. I read that it doesnt effect the woman & Ive gotten preg. b4 while using both these things, though I am stopping the weed smoking b/c im getting scared. I get my period like clockwork, but I havent been to a Dr. yet b/c of ins. issues but we're gonna try using my fiance's ins. to see a specialist. Can anyone help me out here w/ some advice, idk what else to do & its making me depressed??