Hi I Am A 30 Yr Old Woman Who Is

Hi I am a 30 yr old woman who is trying to conceive I am currently on day 37 of my cycle and have yet to have a period. I am experiencing very mild cramping with more pressure than pain. My question is when should I take a pregnancy test to ensure accurate results.? My cycle is usually only 31 days on average and this is the longest I have gone without a period. I did ovulate about 12 days ago. I just do not want to get my hopes up and end up with a negative test.