Good evening. Baby is 7 months old, not crawling or sitting. Should I…

Good evening. Baby is 7 months old, not crawling or sitting. Should I worry? We're currently undergoing massage therapy. Around 5 months old, he stood on his hands and rocked back and forth, thought maybe he would crawl or sit, but it has been 2 months, no progress. Tell me how old your children were when they crawled and sat. Thank you)