IB or period?

According to Glow, I was supposed to start my period on June 18th. My periods have always been irregular. For the last 7-8 months, my period has been on time, every month. On the dot. In June, I started light bleeding between the 8th and 9th. The next two days, the bleeding got just a little heavier, but not too much. The 5th day, there was not a drop of blood at all. And that's extremely unusual for me. My periods usually last between 7 and 9 days.

As of right now, I have taken 4 pregnancy tests and am very confused. I have 2 faint positives and 2 negatives. Today, I started having some slight cramping. Mostly my right side. When I went to the the bathroom, I had some pink spotting and it was only there that one time. I have been to the bathroom several times after that, and nothing. My period is due in 8 days. Is it at all possible that what I thought was my period in June was implantation bleeding? When should I test again to get a more accurate and clear answer on if I'm pregnant?

This morning, I had more cramps on my right side. I sat down and thought I had started bleeding so I went to the bathroom. When I wiped, there was no blood, no pink spotting. Its was watery cervical mucus. Weird thing is, I've never had cervical mucus just pour out like that. Definitely strange for me! Any thoughts?