Ay, I understand your worry kasi ang medical terms talaga ay nakakadami ng stress! So basically, yung endometrium is the lining ng uterus mo, and when it's thickened especially in the late secretory phase, it could mean a few things, sometimes it's just how your body responds sa hormones during your cycle, sometimes it could be related sa progesterone or other factors na kailangan i-check properly. A few of us mums had similar findings sa aming TVS, and honestly, the best thing is to have a follow-up with your OB para ma-explain niya talaga kung ano ang next steps, kasi depending sa iyong age, symptoms, at other details, ang management ay iba-iba, don't stress yourself muna until you hear directly from your doctor what it means for you specifically. Hoping it's nothing serious, but definitely worth a proper consultation talaga!