Welcome. Wow! he sounds like a right a-hole, and seems like good riddance. You have been through a really tough time, and sometimes when you are pregnant it seems that people want to shit on you from a great height. The best thing is to leave him to it..you cannot force him to be a dad, to grow up and to be responsible. He sounds quite immature and childish..getting his best mate to call you speaks volumes.
As for getting custody..any judge will burst out laughing in court..absent throughout your pregnancy and thinks hes gonna swan in and take your baby..its never gonna happen

, but to be sure get some advice if you are unsure. As for going to the scan with him...im not sure if i would want the magic of seeing my unborn child tainted by someone who thinks im lying about being pregnant..! get another scan picture and post it to him! He may come around once the baby is born..a lot of men dont really get theres a baby inside until you start to get bigger! If he wants to be a dad, then let him try..if he lets his child down..then it would be time to step in and re-evaluate the situation.
Its tough when someone lets you down, especially when you really need them to be there for you, but you sound like you have a great support network around you...lean on them for support, and of course on this site.!!
Keep your chin up and TRY to remain strong for your unborn child...
best wishes...