Don't know what to do??

Nicki • Going to be 21 years old soon and ready for baby #1
I am so depressed today. I feel like I let down my fiancé so badly! He thought I was pregnant and I knew I wasn't but still took multiple tests for him including got a blood test because I am 3 days late. I'm very irregular when it comes to my periods. I got my results and they were negative. He won't have sex with me because he still thinks I'm pregnant and it's just to early. I keep trying to tell him I'm not or it would show up. He insists that I am. He doesn't want to mess anything up with the "baby" he thinks is in my belly. I keep telling him I'm sorry honey but I'm not pregnant and I just really want to be intimate and close with each other during this time and he just doesn't want to hurt the "baby" that I know isn't there! Idk how to get him to understand that I'm not pregnant. He wants to wait to be intimate until I start my period. Problem is my period just isn't coming. It is no where in sight. I have no pms signs except breaking out and that started days ago and still haven't even spotted or anything but I know I'm not pregnant! I have an appointment with a specialist tomorrow about my infertility! Maybe the specialist can explain to him I'm not pregnant? And even if I was being intimate wouldn't hurt the baby once implanted! Any advice for me?