Why am I bleeding??

Ok so my cycles are pretty regular 28-31 day cycles my period ended on the 26th, bd on the 27th I am on cd11 we bd last night ovulation is supposed to occur on the 5th per glow. But when we finished there was blood not just a few spots it was down my legs after I washed off nothing more. I have never experienced breakthrough bleeding could it have been ovulation bleed or is that normally really light I didn’t have to put a pad on or anything but again it was quite a bit down my legs. Anyone experience anything like this… PLEASE HELP!