Talk to Pediatrician on Changing Formula Milk

Hy my baby girl is 21 days old....mein ousko mother feed k Saath formula milk b dy rehi Hun. pehly mein ousko BF-1 deti thi. but 4-5 days sy mein ny ouska formula milk change kar k lactogen deina start Kiya ha(due to price of both formula milks, as we can't afford BF-1). ak to milk bnaty huy powder properly dissolve nahi hota water k andar. dusra Mairi baby girl ous din sy daily 2-3 times oose motions kar rehi. aur dudh bahir b phenk rehi ha. so my concern is that 1:is it normal? 2:ya ye sab thk nahi ha? 3: agar ye normal ha to kitny days mein baby thk ho jy gi? 4: ya mujy vapis BF-1 use karna chaheiy. ab ouska to koi reaction nahi ay ga?. kindly guide me what to do