Do I have to worry?

Hey.

I just had my baby 10 weeks ago, and have had abnormal bleeding since about week 5 and a half.. after my lochia stopped I had a pink discharge that came back after a couple weeks, and then I had the depo contraceptive which stopped the pink spotting for 2 weeks before it suddenly returned a week ago. I'm so confused. I have pelvic cramps and rectal pain (but I have external hemmorhoids and apparently, according to the doctor, IBS) and I'm really concerned that it could be symptoms of cervical cancer or something. I asked my doctor for a pap smear when this pink spotting started and she refused me one seeing as I had one two years ago. Is she right to do this? Do I need to worry? I know that spotting can be caused by many things, and also the depo contraceptive injection can cause this but I was spotting before the depo so it panicks me. I have an external ultrasound booked for the 2nd Jan but I'm not sure if they will pick up any problems this way. Am I being silly for panicking and is 2 years too short a time for cancer to become like this? My last pap smear was normal (if they actually did manage to take a proper smear test - I'm getting paranoid it was not taken properly.) I also had a complete STD checkup in the last couple of years which were all normal.

I have had a yellowy/browny discharge ever since I have known but I'm pretty sure I had this before I had the smear too. Could this discharge be normal for me if I have a normal result?