Sakit lutut masa pregnant memang common, especially bila dah berat badan naik, a few of my mum friends complained about this jugak around mid-pregnancy! Try to rest more, guna compression socks, and jangan berdiri lama-lama; a few of us also swear by warm compress atau gentle stretching. But since it's affecting your daily life, better check with your doctor or midwife to make sure nothing serious, especially since you're 22 weeks, they might refer you to physio yang specialise in pregnancy pains.
Eyqadol Alharris