30 Years Old,getting Brown Discharge After Intercourse And Delayed Periods,taking Novelon

Hi Doctor , I’m 30 yr old, married for 5 years. I was on Novelon for the first two years, and we used condoms for the last 3 years, as my husband was travelling intensively, and we saw each other once in 2-3 months. We’re planning a family since November. In December, I noticed some spotting (brown discharge) around my ovulation time (14 days after start of my periods-28 days cycle) after half a day of having intercourse. In the same month, my cycle got delayed by 5 days. So far my periods were fairly regular (cyle of 28 days) for past eighteen years. I don’t understand why the delay happened. This month, we had intercourse on 17th March (one day after my menses ended). I had spotting on 19th March (brown discharge 3-4 times during the day). I don’t understand whether this is normal. Can this be a reason to worry since I’m too old to conceive? I’ve had no problems with my periods for last eighteen years.