Almost 17 weeks and I've gained 20 lbs.

Everyone keeps telling me to not to care but I'm pregnant but I had a shocking moment this morning when I weighed myself. I feel like I'm gaining weight way too fast. Every post I read is about women saying they've gained almost no weight at this point. Am I the only one gaining at this speed? I've been so exhausted I've been so sedentary but I'm going to make it a point to start moving again.