Sorry Tegan, only just found your story!
I was 19 when I had my first baby, 18 when I fell pregnant.
In my case the pregnancy was planned and DH and I were married and out on our own, but as long as the baby is wanted and loved it makes absolutely no difference how old you are.
There is a lot of negativity about young parents but not so many years ago 30 was considered too old to be having a baby!
I have a few "older" friends who had their first babies in their late 30's and they have really struggled.
I think that having kids while you are young is a great way to go if you are ready for the responsibiliy. I for one wouldn't change a thing.
It sounds like you and your partner have a good relationship and you have your Mum too!
You will be a fantastic mother!