The most common way of suffering from ingrown pubic hairs is through shaving, its medical term is Psuedofolliculitis Barbae (PFB).
It can be quite painful but with care it can be avoided.
The most important thing is to improve your shaving or hair removal regime.
Make sure, if using a razor, to go with the growth of the hairs rather than against it.
Using a good quality cream or lotions to remove hair will be advantageous and always make sure you test it on a small area first, as recommended in the instructions.
The condition is caused by hairs by curling over and starting to grow in a nearby bit of skin instead of from the original hair follicle. This can lead to soreness and sometimes inflamed skin. Relief can be got from pressing with a hot compress, such as a wet towel, for a regular period.
Wear loose clothing as synthetic fabrics against the skin will only make things worse. If possible go without underwear to allow air to find the source of the rash. There are specific treatments to relieve these symptoms so it will be worth asking at your pharmacist if it does not improve.
The modern trend of regular hair removal especially for women, is making this condition much more common. Those with dark curly hair will be more prone to it. If shaving give the area a very close trim with scissors before using a razor. Using a non-perfumed foam or gel first will also help avoid the condition.