Re: hard red painful bump near bikini line...
You should probably see your doctor and have it lanced.
I've posted before that my husband recently had a similar bump in his groin region. It was like an ingrown hair/small cyst, but it was painful, and when it didn't clear up on its own, he decided to pop it with a sewing needle. Big mistake!
He got a staph infection in his groin which required three trips to the emergency room and having the entire area surgically lanced and then the wounds were left open, stuffed with cotton gauze, to drain.
These procedures (it had to be repeated several times) plus heavy-duty antibiotics finally cleared it up, but he missed a lot of work and it was painful and scary. He's fine now (except for some scars!), but he could've avoided the whole mess if he hadn't gone digging at himself with a unsterilized needle.
I'd definitely advise seeking medical help with any cyst or boil that appears in that area. It's not worth getting a terrible infection like my husband did.
Best of luck.