Protection panties

As personal as it is, all girls know that when it's nearing... that time of the month, you're paranoid. 
Every time you walk up the stairs, you're afraid that you leaked somehow without you knowing.  You wear your sweater around your waist, just in case while walking to the bathroom, something happened when you were sitting down,etc. 
Anyway, I think it would be extremely helpful if there were an underwear that you could wear, without you having to put in a pad everyday of the week that you are on the verge of getting it at any second. 
This underwear would absorb.  And I know you could say, "Just wear a diaper." But no.  NO ok?  It's different.  It's different because it would look just like regular underwear, and it would come in all types (hipsters,  briefs, bikini, etc.)  AND it would be washable.
Meaning that you can get or not get your period while wearing them, come home, wash them, and then wear them again.  Or when you DO get your period, just switch to pads or whatever.  I think this would effectively provide a sense of security in the event of this occurring (which it often does.)
However, they wouldn't absorb non-stop.  For a while, just like regular pads, but also just enough to let you feel a sense of security in case you do get it when you get up from your seat on the train, or while you're walking to school, etc. 
That way you don't have to RUN to the nearest bathroom to put a ball of toilet paper in there.
You KNOW what I mean.



"But they just look like ordinary panties."
Exactly! =D


Help, comments, questions, or concerns greatly appreciated. 
Also, it would help to know that this hasn't already been invented.  And no diapers, pads, or anything like that.  These are unique because you can't tell the difference between them and regular underwear besides that they're a little thicker in the crotch.

I'm assuming that they haven't been, for I have yet to see them in stores in the underwear section (and/or feminine products).