Hi,
There are two options:
1. As you already said 1st-time sex can break hymen and because of that u may have bleeding.
2. As you are expecting your periods, you will be having a soft cervix about to open to let out menstrual contents. vaginal sex can disrupt the flow to earl or delay, can lead to clots with brownish discoloration. Other causes of vaginal bleeding.
1. Infection which can cause bleeding and pain
2. Dryness – due to infection, improper foreplay since it's your 1st-time sex,
dehydration due to inadequate water intake or
diabetes hormonal imbalance because you are expecting periods or
thyroid issue
3. Forceful sex can cause injury can cause bleeding
4. Normal menstrual bleeding (you may have an early period)
5.
vaginismus can be due to anxiety since it's your 1st-time sex.
6. Deep penetration can cause injury
7. Benign or malignant polyp.
8. Foreign bodies
9. Anatomical abnormalities
10. Bleeding disorders
11. Eczema
12. History of surgery
Hope I have answered your query. Let me know if I can assist you further.
Take care
Regards,
Dr S.R.Raveendran, Sexologist