Clomid??

So my cycle is irregular some month they come on time but the past 2 months I've been close to 10 days late. Me and my fiance are ttc. And have for the past 7 months. I just learned about ovulating and the stripe u can take ..and bbt . I have a bbt coming from Amazon but its running late .. my periods are always heavy and I have bad cramps.. I've researched clomid bc I see a bunch of ladies on here that takes it... and how I saw in my research it helps ovulation .. I'm just wondering because it says you can get the generic brand over the counter? Can you get it at Walmart? Or where can you get it without it being prescribed to you? Also , for the ones that takes it. What is your experience with it ??