What to do.....

Soooooo, I recently found out that I am pregnant and my fiancé and I are thrilled except for one thing. My parents. There are a few factors on why I am afraid to tell them but number 1 is money. We haven't had the best year and they have helped us out quite a bit. Then there's the fact that my oldest daughter (19) is living with them while she's in school and recently let us know that she is expecting. I'm not sure how to feel on any of this. I can't imagine having an abortion after such a wonderful blessing but this is supposed to be a happy time and all I feel are mixed emotions. Sometimes I'm overjoyed feeling on top of the world and then I remember this is my life and everything is all haywire. On one aspect I'm thrilled and shouldn't care what anyone else thinks but on another my parents have been a huge help and I don't want to be a disappointment :( help me please!!!