You can't get married in England at 16 without parental consent but you can in Scotland.
If you are thinking of leaving home you need to plan carefully especially if you have a child or are expecting a baby. You need to find out what you will be able to afford and what state support you will have, for example child benefit -
http://www.hmrc.gov.uk/childbenefit/cb-key.htm
Please think clearly and thoroughly about this. It may be much better for you and your baby if you can find a way to carry on being at home. If you really can't do that, make contact with people whose job is to help you plan a way forward, such as social services. Do a google search on 'leaving home at 16' as a starting point.