Every baby has their own timeline, so try not to stress too much yet. Some babies skip crawling altogether and go straight to pulling up or walking, while others take their sweet time, and it's usually nothing to worry about at this age. That said, it might be good to bring him to see the PD just to be safe, especially if you notice he's not meeting other milestones like sitting up steadily or showing interest in moving around. In the meantime, keep offering opportunities to play on the floor and let him explore at his own pace without pressure.