Depending on how bad it is, it can last up to 3-4 months.
Seam (sewing) In sewing, a seam is the join where two or more layers of fabric, leather, or other materials are held together with stitches. Prior to the invention of the sewing machine, all sewing was done by hand.
Seam allowance refers to the area between the stitching and raw, cut edge of the fabric. The seam allowance is an important part of a seam and is usually unseen, inside the garment. Some seam allowances, such as in a Flat Felled Seam are seen and a visible part of the seam. Understanding the anatomy of a seam will help you understand how the parts of a seam work. The most common seam allowances are 1/4, 1/2 and 5/8. Always check your pattern directions and use the seam allowance called for in the directions. A seam joins one or more pieces of fabric.