A week late and 2 neg. Tests?!

Im new here and seriously looking for some insite. Im on cycle day 34, 7 days late on my period. Tuesday I had really bad cramps ans thought I would start my period, nope. Breasts feel swollen and nipples are sore. Still have some light cramping here and there, nothing extreme and this morning I noticed more discharge than usual. I just tested this morning. Still negative... would a blood test really change anything? How much longer should I wait to retest?