Why is my mom acting like this!

So the other day my teacher gave the class protection so i went home showed my mom right away. I showed her how many and where I was putting them! She said ok.....well recently she has been snooping in my room and saying shes cleaning it. So I took the protection out of my sock draw and put them in my pocket. so later today shesits down and says where are they!?! I take them out of my pocket and said IM 18! here is my protection and left. I went back today to see what she did with them and they were gone! sooo i left a note saying...............
OUT RESATLK??? PLEAE!!!!
This was actually my bfs mothers idea GENIOUS!!!!

So why would my mom betaking protection away instead of offereing it incase of teenage dissaster ( well in my case) Let me know all comments are welcome!