Anak, please go to your OB or the nearest hospital/emergency room today, chest tightness with body aches and headache at 28 weeks needs to be checked right away, hindi dapat i-ignore. Alam ko nakakagulat lalo na first time mom ka, but you're doing the right thing by reaching out, the doctors need to see you today para ma-rule out kung ano talaga yan at makatulog ka ng maayos.