Missed period?

I’m on birth control, combination pills and I have been for around 9 months. I started my placebo pills on 03/25 and usually get my period two days after I start my placebo pills. Instead I got my period on 03/26-03/28 but it was different from my usual periods. It was pretty light and dark brown blood, like in the picture below. Usually it’s normal flow that’s fresh blood and I can fill at least one tampon/pad. However this one was pretty light and was mainly just when I wiped or on a panty liner. Could I be pregnant? I am on the pill and me and my boyfriend use condoms every time we have sex. The last time we had sex was maybe like a week ago and we were really careful because I was on antibiotics. I’m just worried since I’ve never had a period like this... is this normal? Should I test?