Hi baby,
as long as you have been having unprotected sex without birth control, then you are at risk of becoming pregnant. You are at risk even if you have missed one pill let alone a whole month. If you took a test and the result was negative, then chances are you are not pregnant, as it's been a little over a month since your last period, therefore enough time has passed to allow hcg levels to build up (if you were pregnant). The fact that your body has relied on the pill for 6 years to regulate your period, it is probably going to take a little while to adjust back to a regular pattern, so don't panic if you are late for a period. In the meantime if you are still worried, you could request a blood test from your doctor and if the result is negative, start another course of birth control pills.
Good luck baby,
suzy