Is it normal to shed when you apply stuff to your scalp and rub?

So for 4 months i havent had any shed AT ALL (using rogaine 5 % liquid)! But today i noticed, while apllying some oil to my scalp (due to dandruff) i noticed some hairs falling out and freaked out! Right now my head is buzzed so my hair is really short like (approx 0,020 inches). Is this normal? I know that a human has to shed like 100 hairs a day, but anyways i was just freaked out because i haven't noticed anything like this since my shedding stopped 4 months ago! :confused: