How to get excited about my pregnancy

I'm 32 & this is my 3rd baby. For the first couple days after finding out, my boyfriend and I were getting along great and I was honestly excited. We got into a fight & even though it had nothing to do with the baby, I stopped being excited. This all happened a little over a month ago & Idk why I can't get excited again! I've picked out themes for both (idk the sex yet) and browsed the cute clothes & even got a little toy....and nothing. This baby wasn't planned & I personally hate being pregnant. My boyfriend and I are getting older (he will be 38 next month and I'm 32) and we weren't going to have anymore kids because we have both a boy & a girl plus I hate being pregnant! I know this is a blessing and I'm 100% sure I'll be filled with joy once he/she gets here but I feel guilty that I'm not excited. Does anyone have any suggestions maybe I could try? Thank you ladies!