Weight gain jumped up?

Brittany

I am 23 weeks pregnant and have been pretty slow to gain weight. At my 20 week ultrasound (done at 20 weeks+5 days) I had only gained 4 pounds since getting pregnant. It’s been about 2 weeks since my appointment and I have gained another three pounds (all in my belly for sure) is that pretty normal to jump up like that or do I need to watch what I’m eating a little better?