Hello, I have gone through your query and understood the concern. When sexual intercourse happens for the first time, the hymen usually gets torn and this causes the spotting or bleeding. sometimes it can be very heavy also. If this intercourse happens to have occurred during your fertile or ovulatory period, pregnancy is likely. To know what is the cause of the bleeding, you need to have a local examination done by an expert to rule out hymenal, vaginal and cervical causes. If you have a missed period, pregnancy tests may be done. Blood test for pregnancy is an earlier method to clarify even before your period is attained. Hope this helps.