Nadi shuddhi ( if i am doing it wrong)

I am performing nadi shuddhi(alternate breathing) for last few days. Every time I am done with one nostril and switching to the other I feel short of breath and have to take breath before I switch to the other nostril.Is it okay to breath in between or I am doing it wrong?
TIA

reduce duration of inhalation and exhalation to avoid short of breath.