Baby goes from back to Belly..but not belly to back?

Ok my 4 month old goes from back to belly has been doing this for sometime...but I know this is harder for him to do....normally they start out with belly to back...he cant or wont go from belly to back...(only went from belly to back a few times) he get LOTS of tummy time...anyone elses baby do this?

[AndiJ78]

All three of my boys went back to belly before they went belly to back. My 2nd and 3rd boys started going back to belly at 3 weeks (no, not a typo) whereas my first waited until 4 mos to do that. Belly to back happened early for my 2nd and 3rd as well. I attribute it to my diligence with tummy time from birth with my younger two boys. My first rarely touched the ground during the first 4 mos of life : )

[kellym]

Great abs!!

[tomel]

Yeah he has been doing this for about a month...he did go from belly to back when he was about a month...but hasnt done it since..the doc said it was probably a coincedence he was going from back to belly since this usually comes 2nd and is harder...but he does this all the time ...I dunno I guess I wont worry...he has good tone...lifts his head 90 degrees ,pushes up with his hands, holds legs strong when on a hard surface etc.