Period? or pregnancy? Help please!?

i'm a 16 year old girl.
I've been getting my period since 6th grade, but i've grown since i got it and has not really been regular for a full year.

I had my period June 12-15 & July 7-10
My boyfriend & i had sex July 13. We used a condom, he did ejaculate but it was inside the condom.
The next time i had my period was August 5-8.

I was nervous that i was pregnant a week before my august 5-8 period (i was having PMS symptoms..mistook them for pregnancy symptoms.)
So i bought a lot of HPTS (3 first response, 3 ept, 1 rite-aid brand one. All of them claim to detect pregnancy 5 days sooner.)
I took 3 of them, then i got my period.
Since i was still worried, i took 4 after. The last one i took was a first response, i took it this past wednsday.
All of the tests are negative.

It's now August 23, and for the past week i've been having period-like cramps (not as painful..but still there.) I've been slightly constipated, slightly moody, tired, and some light pain in my ovaries, sore breasts(these are all typical PMS symptoms for me, but i understand they are pregnancy symptoms as well.)

My question is..its only day 18 of my cycle. is this too early to be experincing pms?
i had a 26 day cycle from June-July
And a 30 day cycle from July-August.
So i know i should be expecting my period within the next week..or week after that.

Should i be worried about pregnancy? I've had 7 negative tests and a period since i had sex (and yes it was definetly a period- not implantation or vaginal bleeding. I had a normal flow, & all my normal period symptoms.)

but i just don't understand why im getting pms symptoms early..?
Please help!

oh, and please don't tell me to talk to my mom or get birth control.
my mom is very caring, and very loving, but i've tried to tell her i had sex before and she just got really mad.
She won't discuss getting birth control with me, and i'm not sure how to get it on my own other than going to Planned Parenthood, and there is no planned parenthood near where i live..the closest one is about 3 hours away.
I plan on going when i get my liscence (within a month.)
And until i know im doing ALL i can to be protected, i'm not having sex.
I made a mistake before, i regret it.

You're too young IMO to be sexually active and you're too young to handle the responsibility IF you were to become pregnant. You are very likely not pregnant since you have gotten your period since you've had sex. I wonder why this worries you so much because you obviously know that periods, though sometimes very regular are not always to be counted on to show up at the exact same time every month, along with PMS. And the symptoms you mention are also normal for your period. You need to stop being sexually active until you have talked to a doctor and been examined. They are the ones who can tell you exactly what you need to know, and unfortunately you will need to go through your mom to get an appointment.

your probably pregnant i would say u are. go to the doctor and make sure u tell him or her ALL of your semptoms.Its the only way 2 be sure. take care.