What could be going on?!

I have very regular periods. But the past few months have been weird.

They come at regular time and last regular time. But two days after it's ended I will bleed for a few hours then it will stop for good.

But this month it only lasted 3 days(which usually lasts at least 5). Then 3 days went by...and I started to bleed around lunch time, it lasted for about an hour.

This has happened for past 2 days. I start to bleed at lunch time for only an hour.

What could be going on?!!

P.S. we are trying to get pregnant and no luck yet. Idk if this means I could possibly be pregnant or not. I know I should take a test but just haven't yet.