Another period after 18 days

I got my period again after 18 days. My normal cycle is about 28-32 days apart. The first two days it was brown and only light spotting. Then day 3 and today day 4 it is heavy and bright red. It is my normal full on period. I’m 47-years old and I haven’t taken birth control since I was 23. My partner uses condoms and I don’t believe we’ve had any condom malfunctions. Could this be a sign of peri-menopause, pregnancy or something serious? Kinda worried as my cycle has never been irregular. Anyone experience this before?