Hi all, this is my first post, and it may be a dumb question, but I really need insight.

I’m 35 and just started TTC. In my TWW now, and I find myself almost afraid to exercise hard or go for a run for fear that I may do something that messes up my chances of implantation or ultimately getting pregnant. My sister in law has warned me about running too much, as it may effect period regularity. I have done several half marathons and frequently run longer distances, but have stopped since I am TTC. My periods have been regular since I got off birth control 4 months ago. Is it okay to go for an occasional run in the TWW (or anytime while TTC) or should I find other ways to stay healthy and in shape? Any insight would be greatly appreciated!!! ❤️