Uy mama, that sounds really uncomfortable talaga, especially pang-10 weeks pa lang when baby's still so tiny, usually it's more posture or ligament stuff at this stage rather than baby's position causing direct pain. Pero honestly, the fact na mahirap ka mag-stretch and limited ang movement ng leg, I'd really encourage you to check with your OB asap because that kind of nerve or muscle pinching can get worse if hindi addressed, and you don't want to be limping through the rest of pregnancy, no? A few of my mum friends experienced similar lower back pain early on and turned out iba-iba ang cause, one was just bad posture from being pregnant and adjusting, iba naman was piriformis syndrome, kaya talaga kailangan ng proper check-up to be sure. Fingers crossed it's something simple na ma-fix lang with the right stretches or position adjustments, but please don't wait, mama!