I've only had implantation bleeding in one of my pregnancies

When did it start? 4 days before AF was due
What colour was it? Brownish blood
How long did you have it? Woke up with it on a Friday, had it when I wiped all day. Then had slight amount of spotting on the Saturday.
Did you have any cramps/back pain? Nothing at all around the time of the bleeding but cramps the week before
Did you have any other symptoms with it? Was exhausted and quite hot

Good luck!