Twins???

Long story short I had a tubal reversal so my doctor has done two ultrasounds and two HCG blood tests to make sure it's not an ectopic pregnancy. I don't have any systems point at that. In 48 hours my levels went from 4,000 to 14,100. My doctor says everything looks fine but couldn't see a lot in the first ultrasound. Anyways twins run in my family and my husbands. This is will be my 5tb baby and everything seems to be happening much faster and more so.

Could this be twins???