Period Tip/Trick

So idk if you ever heard or thought about this but here is an idea that I discovered about a year or two ago when I was very curious. So, if you are about to start your period and you may be a day or two late, you obviously can’t open up your lady parts and be like hey you comin?? So what I did is I got a cue tip and stuck it up there then took it out, if the cue tip was yellowish brown color I knew I would start in about another day if the cue tip was pure white I knew it isn’t coming for awhile. So just alittle tip you can tetit out.