My body is confusing me....I have no idea if I'm pregnant or not?

Okay, let's start from the beginning.....

Around the end of February I noticed that my monthly cycle was acting a little weird. It was supposed to show up on the 25th which it did but it was shorter than usual and the amount of blood went from light to heavy and vice versa. It only lasted 2 days when it usually lasts around 3-4 days. I chalked it up to being sick with a UTI and thought nothing more of it. However, when I started having symptoms that I NEVER had before, regardless of what me or my body was going through (ex: stress, change in diet, etc.) around the middle of March (such as sore breasts, tender thighs, weird cravings, much more fatigue than usual, easily tired out, mood swings, slightly rounded stomach) This is when I began entertaining the idea of pregnancy. I backtracked and realized that I had sex the day before and the day after my ovulation day in January. Almost every symptoms that I just listed, when I had them, I looked them up and it was almost always knocked down to pregnancy. Every posting I read told me to look out for the missed period as the biggest sign and that's what I was doing. My period for March was supposed to show up on the 24th...it didn't. Instead I got some clear-like/light brown discharge (what I thought was implantation bleeding) from Sunday until late last night. Last night, I got up some bright red bleeding that only got heavier as the day went on. When I got in the shower a few minutes ago, I noticed it was so heavy that it had stained my inner thighs good. Sooooo....at this point I'm confused. Was the light brown discharge I had implantation bleeding or just my period showing up later, even though it has never done this before? Has this happened to anyone else? Is it a sign of a oncoming miscarriage? Is this normal? I haven't taken a test because I'm afraid of a negative result, should I take one? I am so scared that I forcibly ended my possible pregnancy by not being careful and me and my husband really want a baby as soon as possible. Any answers would really help. And as I type....my right thigh is beginning to tense and hurt.