Trusting your SO again!

Right before I found out I was pregnant I found out my husband was texting another women. He said she was only a friend and he offered to give her a ride to work because she was going to get fired. He was deleting the text messages though and didn't mention offering her a ride. So any way you look at it, it was wrong. Long story short I forgave him but its been so hard to trust him again. I don't want to be a jealous wife and I want to trust him but mind keeps going back to him going behind my back. Any advice for me on how to get these thoughtsnout of my head and trust him again. It doesn't help that I'm pregnant which makes me more emotional. I love him a lot.