Eh, meniarap and menonggeng tu memang normal at this stage lah, bayi explore positions dia sendiri, and some babies really prefer that position for sleep sebab rasa secure! The fact dia dah pandai meniarap at 3 bulan is actually good sign of development. Crawling takes time though, so 4 months and not crawling yet is completely fine, every baby moves at their own pace. Re: the post-jab fever and reduced feeds, yes that can happen, but since you're concerned about the menonggeng thing possibly linked to worms, worth mentioning to your doctor next visit together with the appetite change, so they can rule things out and give you peace of mind. Once the jab side effects settle (should be soon), monitor if his feeds and energy pick up, and that restless menonggeng might settle too.