Blood test or not pregnant

So I have had very irregular periods, I got off my birth control September 2015 so it's been about a year and I haven't had a period since I got off my birth control. My husband and I have been ttc for 3 months now and the past week I have had multiple symptoms: nausea, head aches, increased appetite, blue veins on my stomach and throughout my boobs/areolas (sp?), I have also noticed a darker line from my belly button to my pelvic bone. My boobs also look a little more full than usual. I took a test and it came back negative but my friends mom said that because my periods are so irregular that I might need to get a blood test to confirm and that hpt will give me false negatives... What do you ladies think?