Hello,
Light & brown periods with
stomach bloating may be indicative of PCOS,
hormonal imbalance, side effects of certain medications, old blood is commonly brown in colour.
You are suggested to get clinically examined by a gynae, get blood tests,
Urinalysis & the required imaging tests done.
Since you had unprotected sex, if you were not on regular CP & did not take emergency CP, you can be pregnant.
You can get urine or blood test for
pregnancy done or your gynae can tell you to get USG(
Uterus) done so that he factor causing discomfort can be detected.
In the meantime you can take antacids to get relieve from bloating, avoid fried, oily, junk food & addictions if any.
Hope I have answered your query. Let me know if I can assist you further.
Take care
Regards,
Dr. Nupur K