Implantation? Please Help!

Le

So we have been TTC for 7 months now, but my cycle has been crazy the last year. It used to be every 4 weeks like clockwork & period would last about 4-5 days. Ever since october last year I went through a ton of stress and I guess that knocked my cycle to every 35-40 days and that's what it has been since then. Last month though it went back to the 28 days so I was excited that maybe my hormones are finally leveling out but the only time we were able to BD was the few days after my period ended. A week later I did a 20 minute run and right after I had a sharp cramp on my left side and when I went to the bathroom & wiped I had a streak of red with clear cm. I NEVER have mid cycle bleeding of any kind like that..

I haven't had any other "signs" since then, other than sore breasts for the past week which I always get before my period so I have no idea what that was? I know it more than likely was a fluke but with my cycle changing maybe I ovulated really early? I know that's not impossible. . I am due to start this weekend if it stays with the 28 days and according to my boobs, lol, so I will see I guess.. Sorry this is really long, some advice from women who have experienced implantation bleeding or ovulating right after your period would be appreciated!! Thank you!!