Help please!

My husband has been lying to me, now while it was over something super small and he knew he have to lie to me he did. His reason was "he thought he could get away with it so he lied". Normally I forgive him for little things however he is a different person and lies to me a lot. It's not what he lied about that upset me, he looked me in my eyes and swore the lie was true, to the point it made me question myself. Of course I have proof he lied and showed him, however he lied about it a little longer before owning up to the proof in my hands. This has mad me question everything!! When we were just starting to day he had an ex who stopped by when I was gone but he didn't tell me. I came back early and he had all our pictures and my stuff I kept there hidden in a closet. Of course I think he had sex with this woman but he looked me in the eyes and promised on his dad's grave that he didn't. But clearly his promises don't mean anything. Before this we have a few fights about his actions towards me the last week, until then we were okay and ttc. I don't know if I pregnant yet but it is possible and still to early to test. I don't trust him anymore and I don't feel the same right now and I'm not sure if I will again. What should I do? What would you do if this was your husband?