When you have literally nothing else, you use what you have on hand. If there's a woman around, chances are they might have an emergency pad tucked away somewhere.
Heck back when I was trying to be someone else, I carried a couple pads and tampons in my messenger bag in case a friend needed one. (still do, they're just in a purse)
I actually have a small but bright orange hatchet (I spray it to help keep rust off it and also to make it super easy to spot from the other side of my campsite) I keep on my bag, mostly for Camping, but I use the same bag when I'm on my bike.
I've started keeping it on, and have seemingly had less people giving me shit when I'm biking through town.