Short period suddenly

Mars

Hi all. 37 here. I’ve always had 6 to 7 day periods. Before and after 1 to 1.5 day of brown.

Last year it shortened to 5.

Last month i had heavy spotting and pain twice and it shortened to 3 days plus the almost nothing first and last day. This month again heavy day 1, and now day 4 is brown and almost nothing.

Has this happened to anyone else??

We start TTC in July. Had an internal ultrasound and thyroid test, nothing came up. I am panicking.