Not enough hcg

So I have a question! I tested on 9dpo 12dpo and 13dpo ! My period is supposed to come in 2 days I haven’t really been cramping it’s been sharp pain like round ligament pain it was so bad! I do feel like I could be pregnant but am I out ? Is it safe to say I’m not pregnant? When I tested with my daughter it wasn’t positive till a month later could it be that I just don’t produce enough hCG to test positive in the two week wait ?