trust me you will know........it will feel like a small bb behind your nipple, normally it starts on the left for me. i would really have some proviron or novaldex on hand which i hope you do. also not everyone gets gyno so dont be too jumpy to fight it. i had to start taking 40mg a day of novaldex with my current cycle cause it came from nowhere and bammmmm it going down real quick. relax and see if it happens hopefully it doesnt but you can also do a search on gyno and there will be a shitload of info if you need it.