3rd baby, freaking out!

Evelyn • 24 & happily married to my 30 yr old hubby! 8 yr old DD, 2.5 yr old DD, 9 month old DS, expecting 4th by surprise! :)
I went to the dr for abdominal pain, possibly cyst and found out I'm expecting my 3rd. Totally unexpected, I have a 2.5 yr old and a 9 month old. Dh and I are totally freaked because of finances and well, it was unplanned. Not 100% what my Ed's is, but I think around May 15/16.