No period and no positive *UPDATED*

I have been on and off birth controls for 2 years. I started a new one back in April. It's a pill that only gives you a period every 3 months. I'm terrible at taking pills so I missed quite a bit. Like any other, when I would miss a few days in a row I would spot. I Started the new pack mid August and then my fiancé and I decided we are ready for baby 2! I stopped taking the pills but haven't gotten a period since. Last week, I had terrible cramps for 3 days straight, waited for my period but it never came. **updated** yesterday and today I've also had bad cramps but, still no spotting, no period, nothing. All pregnancy tests I've taken have been negative still! Could I be pregnant and it be to soon to read it?