Advise late period

Hi,

I have been TTC for 4 years, not eligible for fertility treatment so been doing what we can. My period was due on 12th Feb. Have had no normal period symptoms apart from slight nausea and an occasional cramp. (I've got IBS and bowel issues so this is normal for me). I did a pregnancy test on 22nd Feb which was negative. Do I just sit and wait for it to appear? My GP is saying it could be stress as I had covid at the start of the year but I've had periods since then.