Question about not getting pregnant due to nursing


Hi I just turned 43 and want a kid bad and have two boys 12 and 2 and still nursing . my son loves it and having a hard time stopping! So my question is my doctor skin I’m not getting pregnant cause I’m nursing so I just started last week not nursing all day we are nursing a LOT less would there be a better chance of getting pregnant now? Just curious if anyone knows thanks !!!