Confused

Hi there, so a week or 2 before my period was due I started coming out in red blotches mostly in my abdomen are breast nipple under arms and now on back buttocks . My period is always regular I was due on the 5th of december but it hadn't come I then bled for one day very lightly and nothing after I went to doctors on Friday where I was tested for pregnancy and it came back positive but tonight Saturday I took 5 tests and they are all negative has this happened to anyone I was only at doctors the day before and had a positive please help if anyone knows why this could be thank you x