Took the pill what do I tell my mom?

I asked this same question yesterday on another group and got no reply so I'm trying here.

I took plan b on the 22. I had normal symptoms of headaches and some nausea. On the 30 I started bleeding very lightly and then a dark red and then brown. I've been cramping also.

It's the next day and I'm still cramping and bleeding but a normal period red. My lining is shedding also now. My next period is due on the 13 and my period ended on the 21 or the 22.

So is what I'm having a period or just a symptom? My mom likes to keep track of my periods because she doesn't want me to get pregnant so I'm not sure to tell her I've started or wait until my next period which I heard could be a week late? My mom won't allow me to get on bc and she likes to check my room for condoms etc. so I can't really get anything else besides just condoms.

Btw I'm 18 about to be 19 in September.