Pregnancy queries pre/pos. Period times.

Hi doctor, me and my husband are planning for a baby and have been having unprotected intercourse since last month, I have the regular 27-30 day time intervals between periods, however this time my period did not go as normal and had only thin drops of blood through the day for the regular 1-4day periods,(Nov1-4). Since last 10 days I have been having weirded cravings and nausea, I also have back pain and also the breast line pains a lot, I took home pregnancy text twice but it turned out to be negative both the times. I feel more weaker now uh days and my thighs started paining since today also I cannot sleep in one position for more than 5minutes. Can you please suggested what should I do . I'm freaking out that I might get my periods and thigh pains has always been constant during my period times.