My period hasn't come can I be pregnant??

Ok so late last month and earlier this month my husband and were trying at the time I was supposedly ovulating. I am really clueless about most of this so I thought why not just start with this app.:-) We want to have a baby, but we are not in super planning mode. Well the time my period was supposed to come has come and gone. I have taken 2 pregnancy tests which were both negative. I took an ovulation test just for the heck of it too and that was negative. A little bit about myself that might factor in-  I am 38 and was taking the pill for 8 years and went off it in January. My period was still pretty regular the first few months. I also have increased my exercise (30-40 mins a day 5-7 days a week). Should I invest in maybe another pregnancy test or just wait another few weeks? I just don't know if my period is out of wack or what?! Thank you for any advice you have.