Is it still possible for me to pregnant?

My fiance and I are trying to concieve. I was pretty confident that i was pregnant a lil after the beinging of july, we are not at the very end of july. I had symptoms like fatigue, desire for certain foods, peeing frequently, cramping,weight gain, and because of the weight my feet and ankles hurt, moodiness,always feeling hot, i was naseaus in the moning for a week but with no puking. Then a week or two after i noticed these symptoms i had a lil spotting one morning. Then what has totally thrown me off and confussed me is the day before my period was due i actually got it. it started out spotting but then i had a regular flow. usually the first day i have a pretty heavy flow. ive heard woman can still have their periods while pregnant.im so nervous caz i was really hoping that i was and im really looking forward to it. i took a test about 7 days before my period and it was negative. i wanna take another as soon as im done my period. and i really wanna get a blood test but i want to see if its worth it first. im so nervous, my fiance and would be upset caz we were so stoked