Pregnant before deployment?

I’ve been in love with my best friend for about a year, but never told him. Since he’s about to leave for a year and a half on deployment, I told him how I feel and come to find out, he told me he’s felt the same way. We had sex for the first time about 2-3 weeks ago and I think I’m pregnant. He had to go to a base about 2 hours away for 3 weeks to get ready for deployment. He was supposed to come hone this weekend, but now he’s saying that he’s stuck there until he leave on deployment. He’s been super distant for the past week or so and I feel like I did something to make him upset. He keeps saying he’s just super busy and I understand that because he has been working 24 hours on 5 off, but he leaves me on read all the time now. Should I tell him I think I am? Or wait until I know for sure?