Maternity leave issues!! Advice please!!

Hi everyone I am 12 weeks and am having lots of anxiety about breaking the news to my employers. I work for a small company and we only have 6 employees including my 2 bosses and I am the only female. I am solely responsible for all the sales and marketing which makes this even more difficult. I don't think I am eligible for FMLA due to the size of my company and we have no maternity leave policy in place. Additionally there is a huge conference that I am supposed to attend in August and I will be 36 weeks at the time. I am usually the person that takes the lead at this conference and this could be a big problem. I really want to be able to take 12 weeks off after having the baby. Does anyone have advice on how to break the news or experience with a similar situation? Any ideas on how I could go to my bosses with transition ideas or unique plans of action? Also what is your opinion on traveling a 36 weeks....I really do not want to travel but am worried I will lose my job if I don't.