Putting his needs before mine

I discussed with my husband in March that I was ready to try for a little one, so I stopped taking my birth control. We have been TTC just to see if it would happen. This month I asked to really try, you know follow all the guidelines to conceiving,, and he gives me 3 of the worst excuses, the main one is he wants to be clean (marijuana smoker) but has failed to stop. Recall we have been trying since March. In your opinion do y'all think he doesn't want kids and using his smoking as an excuse?