i think im pregnant or ovulating how do i know for sure

ok im 18 yrs old im been tryin to get pregnant for 2 months now i did get pregnant but had a misscarrage that was almost 3 months ago now i think im ovulating but im not sur i have the kinda thick whit mucus comming from my cervix an im crampin a little i just had sex that nite does that mean im pregnant or what also a day be fore that i had real bad lower back pain too its was bad it only lasted a couple of hours what do i do?plz some one help me answer this on an i have been takin prenatal pills the past week an half can plz email this to me i dont think i can find the page again thanks its _[removed]_