Oo, common yan sa second trimester, lalo na kung hormonal changes at increased blood volume ang nangyayari sa katawan mo! A few of my mum friends also complained ng headaches during that time, at one of them said it got better when she increased her water intake at proper sleep, pero best talaga mag-check with your OB kung persistent or severe na para ma-rule out kung may underlying cause at ma-guide ka ng doctor on what's safe to take during pregnancy, ha.