Hi, I am 16 weeks pregnant with my third child. When I was 10 weeks along my doctor told me I was measuring 15-16 weeks! She suspected twins. I have twins in my family. Also my HCG levels were high & I was a lot sicker this time around. I was really excited. Had 12 week scan & turned out to be only one little bubba. I am still measuring about 4 weeks larger now. Must just be because it is the third pregnancy. I hope all goes well for you. Twins would be hard work but a lovely blessing.