Thank you for writing! Please post your question just once as we can only answer once. Thank you for your understanding.
You didn't actually miss any of your pills - you were several hours early or late and this will not make a difference in it's effectiveness if you're on the combination pill. You also got your period which confirms there is no pregnancy.
We cannot say why you have nausea - it could be due to anxiety or simply being on your period. But pregnancy should not be a factor. A pregnancy test can confirm this for you.