I don't think this is a problem. I don't know why you feel a little strange. If you are worried, you should get the certificate first. In fact, I personally appreciate this practice of keeping chastity before marriage! And you have all reached this stage, I think one year is definitely not a problem for you!
Sometimes it's important to respect your girlfriend's opinion. Well, I suggest you get a license first. Don't think too much. As a man, you must be confident!
I wish you happiness! Satisfied, please adopt!