Sickle cell disease occurs from genetic changes that cause abnormalities in hemoglobin molecules: 1  Hemoglobin A (HbA) . 2  HbA is the hemoglobin molecule found in normal red blood cells during childhood and adulthood. 3  People who do not have sickle cell disease generally have this type of hemoglobin in their blood cells.ickle cell disease is an inherited blood disorder in which the body produces abnormally shaped red blood cells. In sickle cell disease, the hemoglobin in red blood cells clumps together. This causes red blood cells to become stiff and C-shaped.
A few new pregnancy symptoms will be noticed with the rise and fall of hormonal levels when you are 2 months pregnant. Your waistline is increasing even though you have not put on any significant weight. There is a change in the texture of the hair and skin during pregnancy.
The only time you might want to be concerned if it is more than a month either way. Full term pregnancy is bettween 37-40 weeks not exactly 40 weeks. If you have a baby at 37 weeks they still consider it full term. You're due date is at 40 weeks and 37 is considered full term. But there is only one month with exactly 4 weeks(most years) so it still is about 9 months.