Talk to Pediatrician on Related To My Son Of 5 Month And 13 Days

My son is 5 month and 13 days old,he don't lift his head properly,looks upward for sometime and than starts looking downward,and also can't hold things for longer time,mtlb k pkrta h,grab b krta h,lekin bhut km pkrta h r pkr b le to bs khuch seconds baad muthi khol deta h,hath dono almost altime munh m hotay hain,shaid daant nikal raha h, lekin ziada deir laita b nai,kehta h utha k bethay rho ya khara kro,pr kia ye normal h k sir hold na krna ziada deir k liah, mostly hi aisa hota h k hold nai kr pata r hath m cheezain b ziada deir tk nai pkrta kia ye sb is age k bachay k liay normal hai ya nai?? R is late honay ki kia wajah ho skti h, Weight wagera age k lehaz se bilkul theek h,feed b shi le Raha h