Faking syncing

So my sister just graduated college and moved about a couple minutes away from me and my parents house (I’m still in school) so we see each other a lot. About a month ago she noticed me throwing away a pad and laughed about how we were already syncing. I laughed along and stuff but the real reason I had a pad was because I get heavy discharge before my period, and pantyliners don’t work as well for me. Ever since then she always jokes about it, like she’ll ask if I’ve started yet, I’ll say “not yet” and she’ll just tell me I’ll start soon. I nod along and change the subject. I know I shouldn’t be ashamed because we don’t sync but like I feel like it makes us closer?