Paranoid that she is pregnant!

Hey everyone, I just need some help trying to figure this out. Im really paranoid that i got my girlfriend pregnant, I afraid i may have went to a depression. So here's the story: My girlfriend had her period on the may 9th which lasted for 6 days. We had sex multiple times (about 4-5 times) on may 20th, all with condoms (i would say they're not the newest condoms, but no breakage), and i ejaculated outside each time. However a week later or two, she's been frequently urinating and I know this is a sign of pregnancy, I got very paranoid and started researching and then I noticed she's starting to gain weight. She's been doing taekwondo before regularly but not so much lately because of her work schedule, she hasn't gone for more than a month. Her period is about 4 days late now. As far as pregnancy symptoms thats about it. I kept asking her if she feels anything else everyday, and she tells me that she's fine and she knows her body. She said she's not pregnant. But i still get the feeling that she is. Please help me, i need some serious guidance right now, i've been thinking about this every single day please help me.