Wow she is a very pretty girl! Love the tail and dorsal fin, where did you find her?
Usually gravid spots aren't a good indicator of pregnancy, some guppies have them just before birth as lorekeeper said or some have dark gravid spots all their life, even when virgins, and every possible gravid combination inbetween these two extremes.
Based off her stomach size, she is only one or two weeks into pregnancy. You are keeping her with males right? Just be patient and she will drop within the next 3 weeks or so.
Try to keep her out of breeding traps as those can stress her and cause abortions. Just provide plenty of hiding places and she should feel safe and the fry will hide and grow up naturally.
You can tell she will drop in the next week if she is hiding more, being agressive, has a change in diet, looks like \____/ underneath, poops more and has faster breathing.