First things first, you are having perfectly NORMAL feelings about your impending birth. When I had my daughter at 19 (she's now 4 with a 2 1/2 yr old brother) I was scared and concerned about how I was going to cope. While I did have a partner he was useless so I was basically a single parent. I spent 1 week in hospital, the best thing I did as the midwives are really helpful and encouraging. If you plan to breastfeed then I recommend that you don't leave til you have it down pat. Some woman pick it up really easy but some don't. I ended up giving up after week 2 because i just couldn't master it.
When you hold your little boy in your arms for the first time you'll wonder what you were concerned about. smile
Do you have support around you? Thats something you really need too.
Lastly, your NOT a bad mum, how can you possible be bad when your not really a mum yet? Most things will come natural and the things that dont just ask for help with, no-one will think less of you for asking for help or advice. You will receive a huge amount of support in the forum. Goodluck, let us know how you go. I hope for your sake he comes early. smile