What is going on with my body???

Courtney
I was on the bar for 8 months got it taken out in start or May and my last period was 13th July and my period is always on time, normal 28 day cycle last 3-4 days and I haven't had my period since it is not 27th Auguts 18 days late!!! But I had 3 day period like bleed on the 1st of August which would mean I had a 20 day cycle is that usually for your cycle to randomly be short?? And then had implantation bleeding once on the 12th and once on the 13th of August only when wipe looked like light pink water paint and little bit of brown and got a blood test on the 25th but was negative what is happening??? Ever happened to anyone and what was it?? If my cycle was short and happened to be a 20 day cycle and it Infact was my period then I am now 6 days late for my next period or due in 2 days if my cycle wants to be normal and be a 28 day cycle...but no signs of AF coming so bloody confused Also I have unprotected sex every day if that helps