Severe heartburn, nausea, vomitting, dizziness, sore&itchy nipples, dandruff. Am on bc but am terrified these might be signs of pregnancy. Are they/worth taking a test for?

Definitely. The above symptoms may not be pregnancy related but you do need a pregnancy test to help guide you for the appropriate medical care. If + upt, schedule a visit soon with your OB provider. If "-", it's ok to wait & see if you improve versus seeing your regular doc. Cost wise, it's worth it & most OB offices still offer free pregnancy tests. Take care.
Not particularly. If you are consistent about taking your BC your risk approaches 1%. If you are paranoid you can always take a simple urine test. I see many available over the counter in dollar stores. If your periods are regular & on time I would consider testing only if your cycle is delayed. .