Ay oo, normal yan sa pregnancy mommy! Marami sa amin ang nakakaranas ng ganitong sleep changes, one of my friends swears na gabi-gabi lang sya matulog ng maayos kaya nag-adjust lang sya ng schedule, at ako naman puro power naps sa hapon hehe. It could be the hormones, anxiety about pregnancy, or just your body adjusting to all the changes, kaya hindi ka mag-isa dito! Try to rest whenever you can kahit hindi regular bedtime, at kung tumatagal lang and it's really affecting you, better check with your OB just to be sure everything's okay.