My nipples have been sore for approximately 2 weeks which is a sign that my menstrual will soon start. Usually the soreness begins 3-4 days before the start of my menstrual. I am now 10 days late. I took a pregnancy test on the 7th late day and it came back negative. I stop taking prednisone for my asthma about a week ago could this have anything to do with my cycle being thrown off?

If it can help can you reflect back to before your breasts were sore? Were there anytimes you may have seemed to start your cycle. Usually a few days after conception there's a light almost pink discharge that resembles a really light period that lasts for about two to four days this is usually a clear cut give away that the sperm did implant itself into the egg. Some women confuse this as their menstrual cycle and rule out pregnancy. Sometimes it's so light that it hardly goes noticed. Some take home pregnancy tests can give out a false negative. What time of the day did you take the pregnancy test? Time of day can skew the results as well. They measure hormones present in your urine that women tend to develop only during pregnancy concentrations of this hormone is higher during early morning and level out as the day commences. Try taking a few more tests again with varying brands if testings after you wake up before you urinate. This makes the hormone easier to detect because the concentration is higher and less diluted with other urine fluid. If you're still in doubt you can go to a clinic or planned parent hood and they can do more testing or check your blood which is more accurate than urine

You tested too soon. Wait until your period is at least 2 weeks late, then test using first morning urine. If that test is negative, wait for the next period, and if that is missed, test again or get a blood test done.