What age is she? I had one that laid like that for the first 2 months of her laying, now she lays one almost every day and sometimes 2. She is also the only one I own that will lay after dark. If she is new to laying it may it be nothing to worry about. Some things that effect egg laying are molting, lice/mites, malnutrition, reduced daylight hours (usually in winter), stress, worms, and illness. We need to know a little bit more to direct you to the answer.
1) How old is she?
2) How long has she been laying/ what was her average before this?
3) Have you checked her vent for signs of lice/mites?
4) When was the last time she was de-wormed and with what?
5) Is she missing feathers/ a lot laying around (more than usual)?
6) What do you feed her?
7) Have you felt her stomach for a mass?
8) Is her comb pale?
9) Have you moved her house or coop recently?
10) Any signs of illness?
It is possible that it is worms but it is also possible without the external parasite problem that it might be a molt. Mine were about that age when they went threw their juvenile molt and it is the right time of year for one. Check to see if there is more feathers than normal on the ground and coop floor, if there is than your answer is a molt. For molting increase protein to quicken the regrowth process and return to normal egg laying.
Any chickens that touch natural ground have the possibility for worms and there are many ways to treat and or prevent worms. Going the natural way would be to add a TB of apple cider vinegar with mother in it in the water (1gal) to help prevent, and adding crushed garlic to the feed for treatment. Chemically way would be to treat with Valbazen. A normal load of worms is not a bad thing as all creatures with blood have a few, even humans. It is when there is an overload that it causes a problem for the chicken. I free range in a large half swampy half dry area and treat mine with Valbazen once a year and garlic twice a year just to be sure. It is a personal choice and many choose to treat more often or not at all. If you ever see worms in the poop there is an overload. Pale combs are your first sign that the chicken is not feeling well.
Check for the extra feathers first as a molt seems most likely in your case.