Hey there š
Unfortunately that does not look like a pre-flower. I think your plant is showing itās gender- and itās not good.
If you are growing other plants, Iād separate them as soon as you can- keep an eye on it, but once then start growing male pollen sacs, they donāt stop. I found one just like this is my tent last week. I used tweezers to pick them off, and will be removing him from my tent later this week once the weather in New England cooperates.
Some strains are more likely to hermi on you, sometimes the plant just gets stressed and hernia as a survival method.
Best of luck- and happy growing š±