I have had an average cycle length of 29 days for about 15 months. We have been TTC for the past 3 months. This 4th month on day 22 of my cycle we were having sex and when we were done there was light red blood. Not flowing but definitely not just spotting. The next day (today) no bleeding, but slight discoloration when I wiped in the morning. Could that be implantation bleeding? I've never had a 22 day cycle. What else could it be?