Feeling worried, any advice needed plz (TMI)

Marie
My period was 3 days late. My husband and I have been ttc and I had never had a missed period in my life so I was thinking I had a good chance of being pregnant. I took a hpt and it was a faint positive. 3 days before my period also gave my a faint positive. I was planning on testing again the next morning. That same night we had pretty rough intercourse and I noticed that when I wiped afterwards, the toilet paper was a little brown (like spotting). I ignored it. The next morning I had BRIGHT red blood start coming down. Right away I assumed my period. It's been 2 days now and it's been a very heavy and painful period. Cramps made me feel soooo dizzy yesterday and when I push my urine out, my pelvis somewhat hurts on both sides. Is this all something I should worry about? Was this a chemical pregnancy? The bright red blood is part of what threw me off the most. The 1st couple days of my periods are always of dark blood. The late period threw me off also.