Will I have sagging skin after liposuction if I don't get a tummy tuck? (photos)

From your photos it appears you have abdominal wall laxity, likely from previous pregnancies. While you may not have loose skin after liposuction, I'm not sure you'll be happy with your abdominal contour. I encourage you to visit with a board certified plastic surgeon near you to discuss your goals for surgery. It may be better to wait until after you've finished having children and then get a tummy tuck.

Thank you for your question and pictures. I would recommend you a tummy tuck with liposuction for betters results. If you're willing to travel, Surgeons in the Dominican Republic have experience and very high standard of excellence when it comes to plastic surgery. I'm positive you can get what you're looking for

I agree you don't have extreme loose skin from your pregnancies. Liposuction will not give you saggy skin because your skin is very good after 3 pregnancies, although the skin will possibly be a bit looser than what it is now, but still within acceptable limits.
However, that doesn't mean liposuction is a good choice for you. My concern is that the lower abdominal bulge that you have may be in part from a rectus diastasis and weakness of the abdominal wall, which is repaired with a tummy tuck. Which means you may not be happy with liposuction alone.
I recommend you see a plastic surgeon in consultation because a physical exam is necessary to provide you with more information about how much of the bulge is fat under the skin and how much is from a diastasis. This will help you decide if it is worth it to do liposuction.
As you mentioned, many people are happy with some liposuction and consider a tummy tuck later.