could i be preggo?

my last period was feb 28th n ended march 5th well my period hasnt come on this month n im wondering if i might be preggo. mainly because the fact that march 8th-14th i had unprotected sex wit my boyfriend not knowin that the 12th-15th i was ovulating. my period is generally suposed to start on the 29th but there is no sign of it coming. what thru me off was the fact that march 22nd i started to bleed so i put on a pad thinkin it was my period n then it stopped the vry nxt day i continued to wear a liner just in case it was my period but it was only a lil spot there that was a brownish red color then i wld only see it when i wiped. now i have noticed a slimey discharge wit a lil red tinge to it everytime i pee. but still no period i took a test friday n it came up negative. lately i been feeling sick to my stomach i have been having lower bck pain n have been super tired. should i wait a wk n take another test 2 c if im preggo