You could get pregnant due to the fact you miss taking the pill on certain days. If you don't want to get pregnant maybe you should use a different type of contraception such as the implant so you don't have to worry about it.
Even if it is the straight pill? I don't get my period but I had a break through a few months ago.
Sorry I guess because I'm from the UK I don't fully understand now what you mean by "straight pill". I take the combined pill "Microgynon" where I take it for 21 days and then have a 7 day break where I get my period. Generally from i've heard getting a break through whilst taking the pill can indicate pregnancy.
Straight pill is when you just keep taking the hormones and don't take the placebos aka sugar pills. I don't get my period at all but I had a breakthrough where I ended up getting my period. And Now I am curious as to if I may be pregnant because I haf the breakthrough and had un protected sex durring and after my period came.
I know that with mine if there's break through bleeding it could be that I was pregnant. I guess if you're uncertain take a test or go to your doctor to get a blood test done to be more accurate.