Ay, alam ko yan feeling, gusto mo lang mag-relax, diba? Best to double-check with your OB muna about head spa at four months, kasi depends kung gaano ka-intense ang pressure and kung may chemicals involved, pero generally okay lang ang gentle head massage habang preggy as long as walang harmful products. I'd skip the super strong pressure ones and stick to light, relaxing treatments na alam mo kung ano ang ginagamit nila. Enjoy your pampering once your doc gives the go-ahead, deserve mo yan, mama!