Ay anak, that kind of pain especially affecting your walking ay kailangan talaga i-check ng doctor mo, pwede kasing nerve-related or positioning ng baby, at hindi dapat i-ignore sa 25 weeks pa lang. Please make an appointment soon or go to your OB, ha? A few of my mum friends had similar issues, at iba-iba ang cause nila, some needed physiotherapy, iba naman okay lang after a certain position, pero kailangan talagang ma-assess ng professional para safe for you and baby. Don't wait if it gets worse or nagkaroon ng other symptoms, mamsh. Take care!