Many women experience this type of menstrual flow. It is not related to any fertility problem and should not worry you at all.
You are most likely to ovulate 14 days before your next period is due to start (this is often said to be day 14 when the first day of the cycle is counted as day 1, but this only works for a woman who has a regular 28-day cycle). If you have intercourse often enough, then it does not matter when you ovulate. There is no reason to let your partner’s sperm count ‘build up’ by avoiding sex on days when you are not ovulating. Keep trying, the sperm will be stored for some time in your cervical mucus.
Incidentally, from a research point of view, the first day of the cycle is usually defined as the first day you require sanitary protection.