Help trying to conceive

Michelle
Hello everyone. I'm michelle 23 y/o aa  female. 
My boyfriend is 23 as well 
We went from having sex 5 times a day to now like 5 times a week if that. 
Every time we have sex he cums in me of course.
I have never been pregnant nor has he every had a girl pregnant to my knowledge. 
He does live with MARSA but the doctor said that wouldn't affect anything. 
We have been Ttc since jan and nothing yet. My period in April was 8 days late but still no baby. My period is irregular and its shifts like every 6 months I think. I do track it to the best of my ability. But any suggestions.