Unusual Menstrual Cycle, Seeking Advice

i only finished my last period 10 days ago and noticed a bit of spotting the last couple of day, then its as of i have started my period again today. my periods are usually very regular and I can track them to the day, so this is very strange for me. I have some lower abdominal pain as well, but my periods are usually painless with just some nausea. I'm a bit concerned about what's causing this but think it's too early to go to the doctor yet. any ideas?