I'm an 18-year-old female and I misled my boyfriend, who is 20, about my age when we first started dating. How should I tell him the truth after a few months of not being honest?

I met my boyfriend when I was 17 and he was 20. At the time, I misrepresented my age because I didn't expect us to last beyond a few dates. I even tried to self-sabotage the relationship to escape the situation I had created, but he proved to be incredibly understanding and stuck by me through all the ups and downs. We connected on an app where I had my profile listed as 19—initially, I never intended to meet anyone from there; it was just for fun. When the topic of my age comes up, I’ve gone along with the story instead of clarifying the truth, though I don’t justify my actions. Fast forward almost a year, and I've fallen deeply in love with him, and we're now engaged. Yet, I still struggle to tell him the truth about my actual age. I know there’s never a perfect time to reveal something like this, but I’m at a loss for how to approach the conversation. I feel terrible whenever my age comes up, and the thought of losing him terrifies me. What if he reacts negatively? I recognize that what I did was wrong, but I’m unsure how to rectify the situation. On top of all this, I’m now pregnant with his child. I made sure to wait until I was of legal age to meet him in person, so there was nothing illegal about our relationship—just a moral dilemma I'm grappling with. Any advice would be appreciated.