I don't like to ever advise someone that there is a certain time you 'should' have a conversation, since I don't like to use the word should very often. Most of these things can be solved by the person feeling into the situation and from there trusting their feelings.
No one can tell you when the right moment to speak about something will be. You have to feel that one out for yourself and you can do that by getting in touch with how you actually feel.
It's an exciting time, the start of a new relationship, and I don't want to put a downer on that BUT I think it is important to bring you back to earth a tad by saying that no one is really perfect.
You both have stuff in common, and you may feel that he is perfect for you now...and enjoy that feeling, but keep in mind that it is very common for people to go into a relationship thinking the other person is perfect, and then later, when the honeymoon period is over, it becomes obvious that the person isn't really as perfect as you once thought,..and other parts of them start to come out...so that is worth watching out for, so you aren't so disappointed when the reality sets in. He is putting his best self forward now though, which is natural when things first start out.
Relationships are about learning to accept a person warts and all, but for now you are just free to enjoy every moment together and when the moment feels right, if you feel that it is important to tell him, then you can approach the subject. Make sure he is in a receptive space to hear it though.
Trust yourself is probably the best advice I can give, though that can be hard when you have PTSD, or just generally as people are not really taught to trust themselves. Do you meditate?