Irregular bleeding on birth control!

I’m a mom of one and never been on birth control since now (I’m 24) I got on the mini pill (norethindrone) I’m on my 3rd pack and lately this lasts 2 weeks I’ve noticed off and on spotting I’ll have it heavy in the morning then goes away then comes back and so on. Im just asking is this normal? Has anyone ever experienced this on birth control? I don’t have any other symptoms and I haven’t missed a pill but I did actually doubled on pills 2 and a half weeks ago thinking I forgot to take my regular pill

and thinking maybe that’s what caused it. Any advice I appreciate it 😫