So - I just went to order a refill of my birth control pills and found that I can't until next month because I SHOULD still have a month left...

I keep my unused packs in my nightstand drawer and when I open them I put the open pack in my bathroom drawer because I always take it just before brushing my teeth.

I live in a house with my SO (whom I know didn't take it), our 20 month old son, my 11 yo niece (I have custody of) 13 yo son and 17 yo son (whom I know is sexually active and has had a girlfriend for about 5 months now and I've given him condoms when I first found out). First thought is that my 17 yo son took them for his girlfriend. But I also wonder if it could have been my niece as she recently started her period and has been acting very strange the last few months, doing things that don't really make sense and just saying "you wouldn't understand" for literally everything! She also seems to want to do a lot of "teen or adult" things like shave her legs. And she lies constantly.

Opinions? How would you handle it?