Would it be weird to bring a chair cushion?

Last semester I took all my classes online and unfortunately this year, there was one class that wasn't offered online. I've forgotten how awful the desk chairs are. I go to class immediately after work and my current class is a little over 3 hours long as a combined lecture/lab. The lab is fine, but the lecture room has those terrible chairs that are connected to a desk. It's giving flashbacks of middle/high school. Would it be weird to bring a cushion? This semester just started but I'm not sure how long my back will last 😅 I don't want to look weird though. Thanks in advance for any advice!