ovulating sooner than I thought?

[princesseggo]

I'm fairly new to ttc and have decided to use ovulation tests to get a good idea of where I am in my cycle. My last period was on January 17th and the app that I'm using says I'm due to ovulate in 3 days. I've just took an opk and I know it isn't positive just yet but I expected it to be blank. Does this mean I'll ovulate sooner than I thought? My cycles are around 28-31 days long.
Help!!

I would say based on that opk that 2-3 days is about right, because from when it's a blazing positive you still have up to 48 hours till the egg is actually released.
When the opk gets that dark I would do another after a 4 hour hold (no liquids if possible) to see if it's even darker, then after that the OPKs should go lighter again over the course of the next day or two.