Am I possibly pregnant??

[neeky-neek]

Hey,
I am really in need of some advice.
Okay well I am seventeen years old currently and last month had sex with my boyfriend (of 2 1/2 years) about four/five times through the course of the night during my middle of the cycle stages, because he has medically diagnosed ejaculation disorder we did not feel like condoms were nessecary as neither of us had any STD's.
Problem is I think something went wrong. Lately I have been feeling drowsy,dizzy, the circles on my breasts are starting to grow and they feel heavier than they used to. My last period arrived on time but instead of being a week and a bit long as usual this time only lasting 3 days, along with some spotting i experienced yesterday.
Sleepiness is probably the biggest change I have noticed generally i am out of bed for my 5am starts for rowing but I have found myself going to bed at seven, and whenever, I can sleeping in well until late afternoon and doing the same thing again the next day.
I really need some help, I take my school really seriously and also my sport, so pregnancy isnt something I can do.
But with how strict my parents I don't think I have much choice but to keep it.
If I am I will keep it, and my boyfriend has agreed that thats okay, because we have been together long enough to maybe go that serious and because we know an abortion is out of the picture, as far as the cost, parental issues and so on.
May I please have someones opinion as to whether or not I should bother taking a test, and any advice on anything would be brilliant.
i have no clue at all what to do, all i know is i have a gut instinct i may be...

Thanks
~Monique