Answers please

So Sept 19th I started what I think was my period. I used 1 tampon and after that only a panty liner for the next 4 days. There was maybe a spot or 2 throughout these days. When I wiped it was light pink and kinda had some discharge. I never got heavier. I've noticed some acne which I never get unless I'm on my period. Should I buy a test? Was this just a light period? I'm so afraid to buy a test and have it be negative. I'm thinking of waiting to see if I start again in 2 weeks but nervous.