How likely is it for me to be pregnant?

Around a few months ago I started to get this gut feeling that I could not have kids, which is something I've always wanted. I've had unprotected sex with my one and only boyfriend/sexual partner a few times since last november, and nothing. Up until this month.

My last period ended the 2nd of september, I usually have a pretty regular cycle, 30 days, and according to a few online ovulation calculators, my most fertile day this month would have been the 14th, but because I was having this 'throw caution to the wind because it's not like I can have a baby anyway' phase, I had unprotected sex on the 7th, 12th, 14th and 15th.

Now, for a bit of tmi stuff. I have light coloured breasts, I have super fair skin and I've never had "obvious" areolas, colour wise, because those parts are usually the same colour as the rest of me, until about three days ago when they have become a few shades darker so that you can see an obvious difference in skin tone.. also, my nipples hurt, a lot.

I've been peeing a lot, I have lower abdomen discomfort, the feeling is not painful, but it is definitely not comfortable and feels kind of heavy.

I've also had light pink 'spotting' for the past two days and my back has hurt so terribly sine this morning.

I haven't got much of an appetite except for cold water and coffee, I'm a tea person so the coffee is a weird thing for me. I've had the urge to throw up many times to the point of feeling it at the back of my throat, but never have actually vomited.

I'm expecting my period on the 28th or so of this month, 22 days from the first time my boyfriend finished inside of me, and 15 days from my 'most fertile period / ovulation' days

What do you think? I'm kind of telling myself it's just my mind playing tricks on me, but I'd like some opinions.