3 fibroids found in the anterior wall of the uterus? Will it grow fast? M 26 y/o.Will it interfere pregnancy? And to the fetus if your pregnant?

Cannot predict. There is no way to predict how fast, if at all, the fibroids will grow. Effects on pregnancy depends on how large they are and where in the wall they are located. Your gynecologist can help you monitor them and provide advice regarding any effects on pregnancy.
Growth unpredictable. The growth of fibroids is unpredictable, however, they do tend to grow due to the hormones of pregnancy. They can lead to preterm labor, miscarriage, breech position of baby, dysfunctional labor, and heavy bleeding after delvery. You will typically be followed by your OB and a high risk OB (perinatologist/maternal fetal medicine specialist) for the duration of your pregnancy.