Would you separate with your bf/husband over this?

I'll try to make this as short as possible so Saturday night my husband's phone goes off (it was 5-6 at night) it was sitting next to me on the couch I thought it was mine (we have the same phone) so I touch the screen and the message says "be careful if you go out" (we had a bad storm) and it was from "norm" immediately my intuition kicked in so I hurried up and took down the number I went up stairs to our bedroom and called the number first time no one picked up then the second time a female answered I hug up (idk why I didn't just talk to her) and text her how she knew my husband ect to which she replied they where old friends from high and made it a point to say she didn't want my husband basically they both made it seem completely innocent I 100% believe my husband would never physically cheat on me but the fact that he tried to hide it pissed me off more then anything we talked about it and I'm trying really hard to put it behind me but it still bothers me we've been together 7 years with 2 kids I'm mid 30's he's late 30's like I feel like we are both to old for the bs seriously any advice or input would be appreciated