By the end of the first month a heart beat can be detected. The embryo will weigh about 1 ounce at this time. Though not completely developed, major organs are formed within the second month of pregnancy. The ears, ankles, wrists, and eyelids are formed. Fingers and toes are fully developed, and your baby starts to look like a tiny person.
Weight remains the same.
Now called a fetus rather than an embryo, your baby continues its growth. In the third month nails will begin to form on fingers and toes, and the buds will form in the baby's mouth which will eventually become teeth. Your baby weighs slightly over an ounce now. Movement will begin during the fourth month, you will only feel it slightly in beginning. As your baby moves and kicks it may only feel like gas, until your baby grows and becomes more active.