is it safe to use Salonpas?

my back muscles and bones have been giving me the hardest time to do anything recently. especially my lower back… i asked my OB if it’s safe to use Salonpas and she said yes. Now, this is my first time to use this… EVER. I applied 4 patches on all the parts that were aching. Two on my lower back on each side, and another two on both my shoulder blades… I just typed it on Google, cause I was curious. It says there to only apply 1 patch at a time. But I don’t know where to put it since these are all the parts that were aching and I was really hoping to get a good night sleep tonight. It also says there that it shouldn’t be used in the last 3 months of pregnancy. I’m in my 6th. Now I’m kinda anxious if I should just remove these. I don’t know. Does anyone have an experience with this?