The best chance of getting pregnant is in the days following ovulation, which is normally in the middle of the menstrual cycle - about 14 days before the expected menstruation. At this particular time the cervical glands produce an increased amount of mucous, which makes it easier for the sperm cells to penetrate.
The mucous has an appearance of transparent discharge. Coupled with a slight temperature increase it indicates that the ovulation is taking place in the ovary. Afterwards, the mature egg is intercepted in the fallopian tube and conveyed to the uterus (womb).
The fertilization takes place in the first third of the fallopian tube. Prior to this, the sperm cells have had to swim a long distance. Normally, only a single sperm cell penetrates and fertilizes the egg. The moment this happens, a chemical reaction is triggered in the egg, which blocks other sperm cells, making it impossible for them to penetrate the egg. These sperm cells die shortly after.
The fertilized egg starts to divide as it moves along. The actual pregnancy is not accomplished until the egg has embedded itself in the uteral mucous membrane. This happens approximately one week after ovulation.
The best chance of successful pregnancy is by having unprotected intercourse in the middle of the menstrual cycle - ideally several days in a row.
After detaching itself from the ovary, the unfertilized egg is received by the fallopian funnel from where it embarks on a journey that takes it through the fallopian tube to the uterus. The fertilization takes place in the fallopian tube when the egg encounters the male sperm. Afterwards, the fertilized egg is embedded in the uteral mucous membrane.