How long should a couple, who's trying really hard for a pregnancy, wait before visiting the fertility specialist?

Me and husband decided to seek for help if we didnt have child after 2 years of marriage. But luckily we got pregnant and only knew it right before our 2nd year anniversary. We had sex regularly. Normal like other people and always look for my ovulation day but not so sure coz my period is irregular. So we keep trying and keep having sex whenever we think its the right time.