Stealing tampons

So I'm just wondering here ... At age 18 I had a miscarriage which is what led to my mother finding out I was sexually active but I've only been for a few months , now today I literally steal tampons from her bathroom because I always tell people "I don't want her thinking anything crazy" even though she should already know I've had sex , but I'm scared to grab one in front of her and of course to even purchase my own .... Do you guys think I should talk to her about it or just let her notice I use them to see how she reacts?? (She's on BC so she hasn't had her period in a while , she hasn't noticed any missing because she doesn't look) And also mothers, do you think she knows I'm still having sex? I've been with one person and I'm still doing it with that one person only thing is that she doesn't know because she now hates em lol .. I'm now 19 , I graduate college this year and basically feel old enough to use them but she still sees me as a baby and is quite strict with me