Ay alam ko yan, nanay! I had low-lying placenta din around 26 weeks, and honestly the best thing I did was just rest as much as possible, no heavy lifting, no strenuous exercise, and I avoided anything that could cause spotting kaya I was extra careful. A few of us sa mum group namin na nag-experience din said na maraming cases nag-improve on their own by third trimester kaya hindi rin lahat nag-end up sa c-section, but I really think you should talk to your OB as soon as you can even just through the phone kung possible para ma-guide ka properly, they might want to monitor you with a repeat ultrasound sa next visits to see kung bumaba or tumaas na yung placenta.