You could have a yeast infection or what I experience with every pregnancy including this one #4 is what they tell me is a hormonal rash. It's awful and doesn't go away until after I have the baby. If you do the otc yeast treatment and it doesn't help talk to your doctor.
You probably have an yeast I infection
Yep. Sounds like yeast infection.
Well, you need to confirm that it is and then get rid of it first. Go to your doctor and tell them what is happening. They will collect a sample and send it out for lab work. Once confirmed, your doctor will likely prescribe Monistat 7 (not 1, 3, or 5). Use it for 7 days and your yeast infection should be cleared.
To prevent this from happening again, keep yourself clean down there. Try not to wear anything too tight especially in summer. Wear cotton panties. It could just be your body though. I find I'm more prone to this problem when I'm pregnant than when I'm not.
Is it serious? What should I do to avoid this.
Sounds like a yeast infection