If you are consultant led or shared care you also get a scan at 16 weeks, another at 28ish weeks then you see the consultant every 2/3 weeks from then till you give birth - i had a scan at every consultant app. Otherwise its 12 & 20 week unless there is a need as tori said for growth scans etc x
Only 2. I'd an extra one in my first pregnancy to check placenta had moved as it was low lying so you'd only get more NHS ones if there's a reason for it.
Thats all you get unless you need growth scans x