Ay alam ko yan, super uncomfortable talaga lalo na sa work! That's actually pretty common sa pregnancy kasi lumalaki ang baby at nagbabago ang posture natin, so the pressure sa lower back at tailbone area gets intense, a few of us moms experienced the same thing around that gestational age. Try switching positions every 30 minutes, use a pregnancy pillow or lumbar support when sitting, at kung kaya mo mag-sit on a donut cushion sa office, game-changer talaga siya! But since it's causing you significant discomfort, better to mention it sa OB mo during your next checkup para sure we're not missing anything, okay?