Is pre natal depression a thing?

I'm worried I'm never going to feel any real connection to this baby. I feel so guilty saying this but so far I have really struggled to connect to it, the idea seems really weird to me, and it doesn't feel real. I see all these lovely mums so in love with their babies already and I feel nothing. I had a glimmer of hope in pregnancy yoga tonight and then it went again and I feel detached. Is anybody else feeling like this? I haven't said a word to my SO or mum and my best friend lives in  Australia so I'm feeling a bit isolated. I feel like I spent the whole first trimester waiting for a disaster to happen so I haven't allowed myself to admit it to myself even- anybody experiencing something like this? I feel like a terrible mother already 😓💙