What Causes Spotting, Bloating And Left Side Pains?

Had my perios from may 9-11.. has sex with my boyfriend may 17,19.20. got my period theis month on june 9th and only had it for a day..the other day while going the bathroom i wiped and saw light pink... past couple days ive been feelings bloated and left side pains occasionalyy. could i be preg. i took a hpt today and it was negative but im also not due for my peiod til july