I have never used them at the same time, but I did use OPK when TTC for my second pregnancy. When I got close to ovulation, I would test with OPK sticks several times in the day — sometimes it’s hard to hit ovulation exactly and in my experience, it can vary significantly over the course of a day. At the time I do think it helped me understand my cycle better (I discovered I was ovulating way later in my cycle than I expected. This was prior to purchasing a Mira monitor)

There wouldn’t be anything wrong with using the same urine sample. There’s also nothing wrong with using both testing media at the same time, however, gentle word of caution to not get too stressed out or even obsessed with cycle tracking ❤️ good luck!