I had sexual intercourse with my husband three night in a row. And on the four day I started to spot blood, then the fifth day I start seeing blood clot the my period came but not heavy, what causes that please need answer

It could be from the frequent sex and perhaps some irritation to your cervix or vaginal wall. This can sometimes occur because of a lack of enough lubrication. It can also be simply because your period was about to start.

If you continue to experience bleeding or spotting after sex, see your doctor as there are some gynecological conditions that can cause this.