Ditto Lucy!
The calender day doesn't matter, and your past cycles don't determine what the present cycle will do. All you can do is track your CM day by day to know whether you're fertile or infertile
on that day. If you weren't tracking CM at all, then it's impossible to say whether you were fertile or infertile when you DTD! It could go either way!
I would suspect the stuff you observed was seminal fluid from DTD the day before. That's pretty common!
Knowing your CM for TTC and knowing it for avoiding pregnancy are a little different. But you can get started tracking right away!
Understanding Your Pattern of Fertility and Infertility | Preventing Pregnancy