A worried sister😕❤️

Hi , Im Bella..

My .. not so little anymore sister has a Boyfriend, They have been together for more than a Year now.

She is still .. Young and Im the eldest😁 so she comes to me whenever she needs advice on Female ‘thingies’

She trusts me with her life and uhm.. one evening she told me that she and the Boyfriend have been sleeping together for a while now.. I didnt blow up on her cause i dont want her to lose my Trust .. Cause I LOVE HER and want whats best for her so i had THEE chat and tried to talk to her about unwanted pregnancies and everything. I didnt know if she would follow my advice and stop doing what she was doing. I should’ve been more strict ..

Point is.

Im 19 , turning 20 in a few days and My Mom is out of town because of work and my BF and I babysitting 🤦🏼‍♀️

She came to me on Monday and said told me that her period never came.. It was due this Monday and its Thursday Already and her cycle is regular .. 🤷🏼‍♀️ Everything looks fine (She uses Glo)😁 ... And just to be sure .. Could she be? You know?🤰🏻 Should i buy a test before my mom comes back next week? Or wait a little longer? Shes never been late and she shouldve started on Monday.. and should have ended (the period) today!

I know i should be able to know these things .. But Im just asking for other maybe better opinions 🤷🏼‍♀️ Please anyone!❤️

I dont know what to think , what to do

Should I get a test , Should I not.. Im confused x