Current medical treatment: marijuana
Stress and taking psychoactive drugs can cause many metabolic changes including a hormonal imbalance. On the other hand, there are many other factors that could affect the spermatozoid's mobility like the spermatozoids themselves or pH of the vaginal environment. The ovum is ready for conceiving 24 hours after ovulation, but sometimes the period is shorter and the intercourse is just not on time. You should keep trying, but avoid taking psychoactive drugs. They can damage both you and the embryo when you conceive.