Feeling heartbroken..

I was with my ex for 4 years. We broke up for good in February of 2019. That was a whole year ago and I thought I was over it but I don’t think I am. We tried to have kids but I ended up miscarrying. He has sex with a girl one time (after we had already broke up) and she got pregnant. She just had the their baby on March 17th. I’m not necessarily jealous but I’m a little sad and I feel guilty for feeling that way. I don’t think he told anyone on social media about the baby or his baby momma so people keep messaging me saying congratulations because they think it’s my child, which makes me feel even worse.. I think I feel sad because he really wanted kids and I couldn’t carry one or maybe it’s because I still love him. Idk.