After you been with your husband for almost 3 years and just finding out that he thought he got a woman pregnant but it ended up not being his.

So here’s the back story I was looking through to some bills in our drawer and I found instructions to a dna paternity kit and I’m like okay so I ask my husband why would he need that he said that this one lady tried to say that her baby was his so I said when did this happen he said a year before we met. But I’m upset because one he told me had not been with anyone for a couple years and two like how do I know it’s not recent or anything so anyways he gets mad that I’m upset but I feel like I have the right to be. Idk what do you guys think ?

Edit: I’m not upset that he had sex with someone before me.