Baby talk!!

So I'm on cycle day 33 and normally my period starts on cycle day 28 so I'm a few days late. I'm afraid of what to tell my parents if I am cuz I'll be 18 in August. I know my boyfriend wants kids but we never really sat down and had a one on one conversation about it. We have been having sex ever since we got together almost 6 months ago but we never used any form of protection or birth control. When should I take the the test? Also when should I tell him?