cramping, naesua pregnant????

my last menstral cycle was on the 16th of june, though my menstral cycle is normally so heavy i go through 2 tampons an hour, i had mild spotting around the 16th of july it lasted for 4 days.... i need to know if i am pregnant or if it is just due to weight loss because i lost about 15 lbs this month. am always tired though but i cant sleep i just toss and turn all night or i wake up repeatedly because i get so sick to my stomach that i cant sleep. not to mention i have to go pee like 30 times a day. and my breasts are really really sore near my armpits. i would normally take this as pregnant but i would only be about 5 weeks pregnant and the last time i was pregnant i didnt get a positive on a pregnancy test til i was 6 weeks in. but i miscarried at 7 weeks. there is a dull ache down there as well even though the bleeding has stopped and i thought that implantation takes place in about 10-12 days after conceiving but the spotting took place at 16 days. please let me know what you think please :-( i am desperate for an answer. if i am pregnant this is not planned or really in my game plan.