In January, I found a grape-sized lump in my left breast. It wasn’t brought to my attention at the gyno’s office, but rather during a mundane and medically irrelevant event: a hug.As my boyfriend and I stood on the subway platform, he pulled me into a tight squeeze, and in that normal gesture, I felt an abnormal pang of pain on the left side of my chest. I shifted my stance to see if maybe it was a “bad angle” — but nope, that spot was tender no matter what direction the pressure came from.When I got home, I did a more thorough exam of the area, tracing my breast until I came across a small lump at the tender spot. Then, I did what any modern hypochondriac would do: I burst into tears and hopped online for a diagnosis.I was pretty sure I had cancer at this point (thanks, Google), so I booked a next-day appointment with my gynecologist. She didn’t think it was anything serious, but she agreed I needed an ultrasound. The results a few weeks later seemed to confirm my dire prognosis.“It’s a solid mass,” the radiologist said, adding that it “looked suspicious and had irregular borders.” Within 20 minutes, I was lying topless on an examination table while a very nice doctor jabbed a needle into my left breast, removing a piece of the tumor in the process. Since nothing good ever has irregular borders , I hopelessly accepted Google’s prophecy while awaiting the biopsy to confirm.After what felt like the two longest days known to man, the lump came back C-word-free. It turned out to be a fibroadenoma , a benign tumor that’s pretty common in young women and something I had never heard of in my life.Of course, I was relieved by this news. But I wish I’d known beforehand that that there is such a thing as a non-horrible breast lump — I could have saved myself a lot of unnecessary anxiety.October after October, the world turns pink to remind us that we might get breast cancer and that we need to remain vigilant. No one could say this is a bad thing: It’s good to be aware that breast cancer is increasing in young women . Plus, breast cancer when you’re young tends to be more aggressive, with lower survival rates.But it’s also true that finding something unusual in your breasts is not uncommon, and it’s often not a sign of something serious. “More than 99% of lumps in women under 30 are benign,” says David Michael Euhus, MD, director of breast surgery at Johns Hopkins. “And for women 30 to 40, it’s about 95%.”After going through this myself, I learned that even benign masses (yep, there’s more than one kind) are not created equal. Some will get bigger, some might hurt, and some might still need to be removed ASAP. With the help of breast experts, we’ve put together a list of the benign breast lumps every twentysomething should know about.