Self imposed shotgun wedding

Teeny • Mom of one, stepmom of one, and expecting our third boy 1/31/16 👶🏼
So, my fiancée and I have lived together for over two years and have been raising our two boys from previous relationships together (we both have custody, one is his bio one is mine). We've seriously discussed marriage over the past year and decided we'd get married next year because we're working on an entire home renovation that won't be done until November. That, the boys, and full time jobs have kept us too busy to  worry about much else.
Well, in May we were seriously talking about having a baby together because he realized he can retire in 18 years and said "if we're going to have a baby, we're going to do it now!" I JUST got a new great position in my organization so I was like "okay we'll worry about it at the end of the summer." BUT A WEEK LATER WE RANDOMLY FOUND OUT WE WERE PREGNANT.
So we decided to get married and have a small backyard bbq party this Saturday. Although we could have a big traditional wedding, I'd prefer not to considering we're paying for it ourselves, we've got to support three kids now (we get no child support), I'm estranged from my parents, and his parents are in no position to help pay for a giant party.
I didn't feel bad about it today. We're nice professional suburban parents with good jobs and great friends with an amazing relationship, but I just feel trashy as hell and I'm feeling really insecure about people making fun of me.
Have any of you done something like this? Did you regret it? Help me. I'm pregnant and hormonal 😓