<human>: Give me the gist of the text in a nutshell

My (22/M) girlfriend (24/F) have been together for almost 5 months now.  She is the experienced one and she is my first serious relationship. 

Right now we are going through a bit of a pregnancy scare, and I'm getting  pretty worried.  We have talked about this scenario multiple times; that we can't handle a baby, can't afford it, too early etc.

The thing that worries me, is that she missed her period for May.
We've talked about it, and she claims that when she is under a lot of stress, she will skip her period for a month.
Does this happen to a lot of women?

Also, it's worth mentioning that she isn't using any birth control.
We are sexually active but I am always sure to use condoms. 
I know they aren't 100% effective, so I would like her to start considering adopting birth control, just to be safe.

Is this a touchy subject for women?  I want her to do some research, because she doesn't know a lot about birth control.  She is under the impression that it will throw off all of her hormones, and she doesn't know of the different types of BC. 

I want her to look into it but I don't want to offend her by bringing it up.
What should I do?
<bot>: GF doesn't use birth control.  I want her to, but I don't know how to bring it up without offending her.