Spit up

My LO is 3 months old and has been spitting up way more than normal. She has now started arching her back while eating. Last night she was so irritable wouldn’t go to sleep until 3am which is not her. She normally goes to bed at 9 or 10 at the latest. She has been teething for the past 3 weeks which is when that’s all started. But I’m afraid that she isn’t getting enough bc the spit up has increased so much. My mom said she’s fine and that “babies just spit up” which is true but she has never spit up this much. I’m going to call my pediatrician after Labor Day but just wanted to know if I’m overreacting.