Chemical Pregnancy

So last week I was supposed to start my cycle on 5/20/15. When it didn't show by 5/23/15, I tested and it come out positive. I took 3 different test. I started bleeding heavily 5/24/15 with a lot of clots and just finished up today 5/28/15 with clots still remaining. This would be the second chemical pregnancy I have had in 5 months. Can anyone offer any advice on how to lessen the chance of this happen in and for me to be able to conceive?