Hi mama! BPS is basically an ultrasound check they do near the end of pregnancy to make sure baby and placenta are doing well, they look at baby's movements, breathing, muscle tone, and the amniotic fluid level. As for cost, it really varies depending sa hospital or clinic you choose, I've heard anywhere from around 1,500 to 3,000+ pesos, but best to call ahead at your OB's clinic para malaman mo exactly kung magkano sa lugar ninyo kasi talaga namang different ang presyo per hospital! One of my mum friends had it done at 38 weeks din and her OB explained it takes like 20-30 mins, very straightforward lang. Definitely ask your doctor din about this since they'll recommend if kailangan mo talaga based sa your pregnancy!