Concerned... New to forum. Maybe Preg. ??

Hello everyone Ayuda Me!! ( Help Me) I really could use some guidance.

Let me start of by saying last month (April 2011) I thought I was preg. But I wasn’t. I normally my period comes on the 28th of each month like clockwork. It normally lasts 3-5 days, first two are the heaviest followed by a numbing day 3 and a lingering 4 and 5 day. On that period I cramped severely, maybe the worse than ever, bled heavily and by day 2 and 3 it was gone. I really didn’t think too much of it.

This round my cycle  has not come. I normally get it like I said on the 28th of each month. Today is May 30th. Now being 2 days late may not concern many, but this is different. Yesterday I woke up to very light spotting, I thought this was the start of my period so I wore a pad the whole day.  There was only light pink blood I guess when I wiped. Today I still had minor more like annoying back and front cramps and now the spotting is redish/brownish and is only apparent when I wipe. I took two tests today. One by Answers when I first woke up. It was negative. On my lunch break at work, I took another this time First Response, at first nothing showed and then several minutes later it showed to be negative.

I dnt really keep up with ovulation and all that jazz, I have a app on my phone that supposedly tracks it, but I am not sure how accurate that is. I have had unprotected sex with my boyfriend at that time for pretty much the whole month of April and May.
Now I have weird symptoms. They may be nothing. But I am extremely tired! LIKE I sleep 8 hrs a night and I feel like I haven’t rested when I woke up, which is unusual. I also seem to be hungry like every 2 hrs I need to eat. Like more than  normal, I feel nauseous but hungry at the same time. And I get nauseous when it’s time for me to go to bed. I think im dizzy because im tired. I don’t know. I want to make an apt with the doctor, but rather wait because I don’t want to pay out that money at this time.

Im 23 and the idea of a baby is exciting to me, but the reality is kinda overwhelming because me and my boyfriend just broke up, we are still close but still... But if I am im worried he would want to get back together due to us both wanting a family, not babies mamas and daddies you know? And I don’t want someone to be with me because of a child. I know I can do it by myself, I have a really good job, but no money in the world can only raise a kid. I know im going on and on.. But ahh nervousness overtakes me! If you have any advice or need more details let me know pls.
I would normally ask a friend or something, but I just don’t want to alarm anyone.