She stayed on the pill into her 40s, until it almost killed her.
It started with leg pain.
"Then it escalated to very short of breath," Krull said.
After several tests, doctors found a large blood clot in her leg.
"They took me down for what's called a CT angiogram in my lungs, and that showed that my lungs were filled with clots," Krull said.
Dr. Penny Tenzer says women need to know about the dangers of taking the pill.
"I have seen several young women have clots on the pill at a younger age that don't necessarily have other risk factors," she said.
Birth control pills quadruple your risk of clots, and on long plane rides, women on the pill have a 14 times higher risk.
Package inserts warns about clots, but Tenzer says doctors should do the same before prescribing the pill.
"I always mention clots when I talk to my patients," she said.
Experts say you should reconsider taking the pill if you're over 35, smoke, have high cholesterol, are obese or get migraines.
"I was more frightened afterwards as I looked back at how bad it could have been, and that I really could have died," Krull said.
Her message is to know the signs of trouble. Severe leg pain, abdominal or chest pain, headaches and eye problems could be an early warning.
They were all symptoms Krull experienced.
"I'm lucky to be alive," she said.
Krull is now off the pill and not taking any more chances.