The way that doctors know how far along a pregnancy is, is by using the LMP (date of last menstrual period), as that is the only known factor. It is unclear when most women ovulate, when fertilization occurred and when implantation occurred.
When you have sex, fertilization may occur that day if you have ovulated, but the sperm can also be waiting at the opening of the cervix for a few days until the egg is released. So, fertilization can happen a few days after sex. Implantation of the fertilized egg then takes another 7-10 days, as it takes the fertilized egg time to travel from fallopian tubes to implant in uterus.
It is unlikely that you were ovulating on/around the date of July 1st, if you were expecting your period 4 days later. This is assuming you have a very consistent cycle every month.
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The way that doctors know how far along a pregnancy is, is by using the LMP (date of last menstrual period), as that is the only known factor. It is unclear when most women ovulate, when fertilization occurred and when implantation occurred.
When you have sex, fertilization may occur that day if you have ovulated, but the sperm can also be waiting at the opening of the cervix for a few days until the egg is released. So, fertilization can happen a few days after sex. Implantation of the fertilized egg then takes another 7-10 days, as it takes the fertilized egg time to travel from fallopian tubes to implant in uterus.
It is unlikely that you were ovulating on/around the date of July 1st, if you were expecting your period 4 days later. This is assuming you have a very consistent cycle every month.
Does that help?
July 19, 2009 - 2:03pmThis Comment
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