Your pregnancy starts from conception which can be done through fertilization or implantation. Here is info about the stages of the baby by month
Month 1
Ranges from 4 weeks – 7 Weeks, what you have are called an embryo with two cell layers where the body part and hair organs will develop.
Month 2
Now your baby should be kidney bean size and move constantly with distinct fairly web fingers. This stage last from 8 weeks to 12 weeks.
Month 3
At this time the baby will be 3-inch long weighing about ounce. It has already developed small finger print which is unique and this stage go from 13- to 16 weeks.
Month 4
You have 5 inch long baby weighing about 5 oz and the skeleton will start to harden to born from cartilage. The stage last from 17 weeks to 20 weeks
The month 5
There is now eyelid and eyebrows and the size is more than 10 inches with the stage lasting from 21 to 24 weeks
Month 6
You have pound and half baby and the initial wrinkled skin will begin to smooth and he will start developing baby fat. The stage last from 25 to 29 weeks.
Month 7
Now you have 3 pounds baby with 15 inch long and can now open as well as close eyes and go in the direction of light. The stage last from 30 to 33 weeks
Month 8
You have about 4 ¾ weight baby and fat is already in the body with the longs developed. This stage last from 34 to 37 weeks.
Month 9
The average size of your baby at this time is 19 inches and can weigh about 7 pounds. The stage last from 38 weeks to 41 weeks and due for birth.