So confused.. am I pregnant?

So long story short..

we are trying for baby number 2.. and I started using opk test strips this cycle.

I was supposed to start my period Saturday.. negative pregnancy test on Thursday and Friday I started bleeding.. pinkish/brownish and then it got a little heavier so I just assumed it was my period and got over it. But it was super light .. way lighter than normal.. and by Sunday I was pretty much done bleeding altogether.

Today I took a opk test and it was positive.. so tonight I took a pregnancy test. And got this... someone please EXPLAIN?!?

Am I just going crazy? Has this happened to anyone else before? I had a chemical last month :/ so obviously scared it would happen again.

Any advice would be greatly appreciated!!!!