Argggg I don’t know what’s going on

Last Saturday (10th feb) I got my period for literally 1 day I usually have it for 3/4 day and is quite heavy but this time it was not heavy at all! I am due my period today (17th feb), I went to the doctors about it as my lower back and tummy was hurting and all test came back as fine no wee infection not pregnant my ovulation is on the is on the 22nd feb , so I don’t know if they tested to early or what I’m just a little confused on what’s happening and how long I actually have to wait to test.🙂