I'm 31, and my periods have always come fairly regularly on a 31-33 day cycle since I started at 13. Nothing remarkable about them - limited PMS, 2 days quite heavy (change super tampon every 3/4 hours to avoid possibility of soak-through) then 3 days of lighter flow, bad cramps and sometimes a mildly upset stomach on day one but then fine for the next four days.
Last summer DH and I decided we would start TTC. Had several monthly disappointments, but figured we couldn't expect to get lucky immediately and kept trying.
Then my November period (due around the 26th) didn't put in an appearance, and as I can't remember the last time I skipped a period I immediately thought - ooh success! But when I tested - BFN. Didn't have time to dwell on it though as Christmas was so busy. I peed hopefully on a few more sticks after that just in case - but got nothing but negatives.
When it got to mid-January I finally got a bit of light brownish spotting and figured AF had belatedly showed up. This went on for about 10 days though and never got going properly. Then the spotting dried up and I got nothing for 4/5 days, and then my period finally showed up properly on 1st February.
I put it down to just a one-off weird blip in my system and thought little of it, especially when my March and April periods showed up in a timely manner and were normal.
Next period was due around 3rd of May... and I'm still waiting for it. I've had very minor crampy feelings a few times - just like period pain lite since it was due but nothing to show for it. I POAS to make sure, but I'm not pregnant according to the test.
I'm generally pretty healthy apart from being somewhat overweight (5' 7, 185lb) 
My blood pressure is perfect, and I don't take any meds or have any illnesses that I know of. I was checked for possible thyroid problems a couple of years ago but blood tests and ultrasound were normal. I only drink in moderation (one bottle of wine at the weekend usually) and my diet is decent if slightly too cake filled.
Has anyone experienced anything like this or has any ideas about what the problem could be?
I may be fussing for nothing, and maybe wouldn't be so bothered about this if I wasn't wanting to get on with TTCing. But as we are, anything that prevents me from getting my hands on a baby worries me.
Obviously I will go to the doctor if this continues, but I'd like to be able to go with some idea of what may be wrong with me so I can be more confident with the doctor, not miss out mentioning any small but vital bit of info and not be persuaded that all is well if it isn't. (If that makes sense?)
Anyone who made it through all that - thank you. Have a reviving 