Suggest Treatment For Irregular Period After Overseas Travel

Hi, my husband and I have been ttc since Mar this year. I have stopped Melodene in Dec10. At first my periods stayed normal. At the end of March I was promoted in my job and from there everything went wrong. I was sent oversees for 2 weeks in June and my period was late. I had my period in May and then at the end of July. I went to see my local docter. She send me for a scan and blood tests and everything was in order. I don't know when I will ovulate because my period is very irregular. Is there anything you can suggest?