Twins again?!

My first pregnancy was twins, though I lost one. I'm pregnant again, but have yet to have my first ultrasound as I believe I'm only 3-5 weeks! Did you guys have any tell-tale signs before you knew for sure?! Last time I was extremely sick, this time I have severe constipation, diarrhea, nausea so bad I can't eat, my ankles are the size of golf balls and I've already gained 10 lbs 😱 I can't help but feel as though it's twins again, and in worried that if it is something will happen again!