Is it normal to experience a lump after having liposuction?

Depends on the cause. of the lump. It could be swelling, a hematoma ,a seroma, an infection..... So see the surgeon to check it out.
Yes. Depending on the type of liposuction that you had, you can have swelling and contour irregularities for several months after the procedure. If the lump is tender or red, it may be a sign of a problem. Consult with your surgeon to make sure it's ok.