First test negative should i retest?

My cycle was due on the 12th and I'm a week late , I took a test at 3 days late and it was negative. I had cramping on the right side for 3 morning straight one day and every since then I get this dull ache cramps on the right. The day of my cycle I cramp bad like my cycle was coming and nothing . I cramp now on and off like a dull ache feeling especially on my right side and even lower back aches on my right side that shoot to the front it last for 5 second. My boobs are even a little bigger. What should I do?!!