This is the second time this has happened..

Last year I had a period in November, then I didn’t have one until March of this year. I took a pregnancy test multiple times. It was negative. I’ve been to the dr and nothing is wrong with me. I’m having the same problem again. I had a period March 1st-6th. Now I haven’t had one since then. I’m just nervous I’m going to end up pregnant and not know it or something. I’ve had test after test and everything is normal to them. Has anyone ever had this happen. It sucks so bad cause my husband and I want a baby. But we’ve had no luck yet. I am 25 btw.