What Causes Irregular Period?

Hello doctor...my problem is that I got married five months back.before marriage my menstural cycle was regular always having my periods two to three days back before my last menstural date...just before marriage my cycle changed and started having periods one day before my last LMP...it's remain liked that till three months even after marriage..than in fourth month again cycle changed and again I had my periods two days before my LMP...now in this fifth month my periods were delayed for two days than my last menstural date my last LMP was 24 April and I got my periods on 26th of May..I'm also trying to conceive for the last two months..I'm worried about my cycle irregularity.. Should I have a hormonal test??