Hmm,my biggest adviae to you would be (if it turns out that you are not pregnant-and I think you are not,cause for those symptoms its just 2 soon) to stop having sex. I mean,if you think thathaving a baby will ruin your plan of life,then you are clearly not mature enough to have sex.
I could say use birth control AND condoms,but BC fails and condoms break..and your thinkin shows that you aren't mature enough for that.
I'm not saying you wouldn't do the right thing,I'm just saying that you would be somehow PUSHEd into it.
If he loves you,hell wait till you will be able to provide a home and EVERYTHING a baby needs before having sex.
Because so really sex means pregnancy,that's a fact to accept before you start being sexually active.
As for now..wait till your period is due,if she's late,make a test,or even better go and make a blood test.
Good luck!