So confused

So I was 5 days late with af , I went to see my doctor as I was having a few odd symptoms, she sent me straight for bloods and did a full set of bloods for pregnancy (e.g blood type , vaccinations etc) she was pretty convinced I was pregnant and to be honest so was I I got the results a few days later and it was negative but I still didn’t have af until I was 9 days late . My period was medium - light flow no cramps . At normally lasts 3-5 days for me and it ended up being about 3 days this time . However the last two days I have had unusual “spotting” that I’ve never had before watery pink discharge . I thought that I peed my pants before because I felt it come out and it was tinged pink . This has been for 2 days I had unprotected sex 4 days ago but I don’t start my fertile window until tomorrow. I’m so confused and have no idea what my body is doing . Has anyone had any experience with this before . I know is not exactly a ttc question but I just had no idea where to post this . Could it be implantation when I’m not even in/passed my fertile window ?