I went in for a pregnancy confirmation appointment at 6 weeks exactly and the doctor seemed surprised by the size of my uterus. She double checked my LMP and was just sort of like, hmm. My HCG levels were normal, but higher than my first pregnancy. I've had this suspicion it could be twins, but I know this could all be normal for a singleton. My first ultrasound will let us know on 2/13. Any other similar experiences, especially with a second pregnancy?