Extremely confused - advice please? :(

Amy
My period was due to start Monday the 1st of August, it's now Thursday the 4th of August and still nothing! I have taken 3 pregnancy tests which are definitely negative. It's probably worth me mentioning that my periods are usually like clockwork and it's never been late before apart from previous pregnancies where I miscarried. Could I be pregnant? Has anyone else had this happen and if so, what was the result? 😊