3rd pregnancy

I'm 14 weeks and 3 days with baby #3. I had an ultrasound at 9 weeks 5 days, it was just a quick one to date the pregnancy, it was done very close up, the baby looked like a giant the whole time, haha. And the sound was off, though we could see the heart beat.

Anyways, reason for my post:

I started showing at 8 weeks. It may have been a little bloating, but I really haven't had much gas, and I haven't been constipated. In fact I've had more of the opposite. And the bump didn't go away, just got bigger and bigger. If I bent forward I could feel my uterus, it felt like a small rock. I needed maternity pants by 11 weeks. And now at 14 weeks I have a very sizeable bump, and I my uterus feels heavy already, when I walk it feels much better I use my hands like a belly band to support my lower abdomen where my uterus is.

Is this all normal for a 3rd pregnancy? Everything just happens way sooner? Or could a twin have been missed on my 9 week ultra sound?

My first pregnancy my uterus was tipped forward and I ended up getting huge, though I was 15+ weeks before I had a noticeable, round, obviously pregnant bump. With my second I had a tiny bump at 12 weeks, but again was 15 weeks before my friends noticed it, and my uterus was tilted back so I never got as big as the first pregnancy.

I've been so big, and started showing so early, family members kept asking if my dates were wrong and I was really a month further along. But that 9.5 week ultrasound said I was only 5 days further along then I thought. I haven't had an appointment since, but my next one is on Friday.