My only friend and her husband

So my friend that just recently had a baby told me around the time she got pregannt she had sex with someone else. Her ex..... Wellllll im very upset im pregnant so this just bothers me alot. Apparently there is a chance the baby coule be his idk though. So these are the facts i have she had sex with her husband and ex same day.... I already know i cringed too at that. Her ex did not cum in her but her husband did..... Omg i just needed to tell someone its been on my chest and i dont know what to do or say... I guess my question is how worried should she be. This just bothers me because im pregant and i guess she just always has somesort of drama. And i never have any