Weird situation with HPTs and periods...

This is something that happened to a friend, not to me. I’m 15 weeks pregnant with my first and a friend of mine is TTC.

About a month ago she got a very faint positive on two hpt and her period was a day late. The next day she started her period. She assumes it was a chemical pregnancy and went on trying the next month.

This month she took a hpt a few days before her period was due... and it was SUPER positive. Like really really dark positive line.

I don’t want to scare her by suggesting it if it’s not possible, but could she actually have been pregnant all along and her “period” wasn’t actually AF? She said it was like her normal periods.