I unknowingly got a married woman pregnant…

I’m not sure how to feel and what to do, honestly this is still very confusing bc I only found out recently. Basically, we’re from the same hometown but I live in a different city, I only go there to see my family. 2 years ago we met at a Halloween party and got along pretty well… We hung out multiple times in the days before I had to go back and after that we didn’t really keep in contact much, not even on the times I visited again but this week I’m back in my hometown and I ran into her, her husband + their daughter… They had been together for 5 years and I had no idea !!! She called me after that and confessed everything, that she had cheated on her husband and that I got her pregnant… What am I even supposed to do, idk wether to tell her husband or keep it to myself bc that’s very serious…