Do i put self-only for only the months i had my own insurance, and none when i was on my parents insurance, or self-only on all of them.

I was on my parents insurance for about half of the year in 2018. After I graduated and got my own job, i was on my own insurance, a HDHP with an HSA. So do I mark Self Only just for the months i had my own plan, and do i mark none or family for the months i was on my parents plan. Also their plan is not a HDHP plan