Late AF & Cervix positions???

Ok ladies, so I am new at checking the whole cervix position? According to my glow ovulation calendar I was supposed to start my period on the 13th of this month and end on the 19th of this month however I didn't start till late last night on the 19th. For the past week I've had severe breast pain and lower abdomen pain in my left and right ovary area thinking that I was pregnant took 4-5 pregnancy tests all came up negative and went to the doctors yesterday came up negative so I took a blood test and low & behold last night Aunt Flo came. I have never had a period a week late since I was a teenager. My cramps are really bad, & I fell asleep shortly after putting in my tampon lastnight & when I woke up this morning at 7:30 I realized for being fresh on my AF I should have had a major heavy flow??? I did cover the whole tampon but no leakage for being in that many hours & changed it once I woke up. Sorry TMI. & changed it at 10:45 half the tampon was still white? So I checked my cervix, it's high, soft & I believe closed? I just wanna know is that normal when AF is in town?