Both of the previous answers are great. A lot of people confuse the two programs, and it's very important to know which one you're on so you can get correct information.

If you're receiving disability insurance benefits (based on your work and earnings, and your monthly payment is generally the same no matter what), or SSDI, the rules are vastly different from someone getting Supplemental security income, or SSI. SSI is a welfare-type program, and every bit of income you have coming in, or even receiving rent-free housing, can decrease your monthly payment.

That said - if you are getting SSDI: Yes - there is a trial work period. I agree with the advise to call the local office and ask to talk to their work incentives expert, but here's the jist of it:
The trial work period (TWP) is a 60-month rolling window during which you can work and earn over the TWP amount ($810 gross in 2016) in 9 separate calendar months without it affecting your benefits. If you're anything like me, it took me forever to grasp what that actually means. You can work and earn AS MUCH AS YOU WANT, and for at least that first 9 months, you will still get your payments. The 9 months can be all in a row, or spread out over the course of 60 months (5 years). If you never have 9 months within the same 5 year period, you will still not have exhausted the TWP. Hopefully that makes some sort of sense.

If you use up the TWP, you then go into the 36 month extended period of eligibility. During this time, they look at your wages to determine if you are performing substantial gainful activity (SGA - $1130/mo gross). However, they look not only at the gross wages; if your employer has made special provisions for you based on your condition, or if you have unreimbursed expenses that you must pay out of pocket relating to your condition that are necessary in order for you to work, these amounts may be able to be deducted from your gross wages when making the SGA determination. During this 36 month period, your entitlement to benefits can stop and start based on whether or not you've earned SGA each month. I encourage you to read up on this and keep track of your own earnings so you know when you are/are not due payment. Even if you submit your paystubs as required every single month, you will almost certainly be overpaid if you work SGA due to backlog and processing time. By the time SSA processes the review and determines that you worked SGA, months will have passed and you've already been paid money you weren't due. If you keep track yourself, you can make sure to set aside any payments that you know you shouldn't have received, so that when they come knocking you've got it ready to pay back.

All of this is coming from my perspective as a 9-year employee working on the retirement/disability/survivors insurance side of things. I don't know how much backlog offices around the country have on average, but I know my own office is literally operating with about 30% of the staff necessary to do our jobs, so it is completely normal for us to take 9 months to complete a simple review, simply because each employee is responsible for way too many things and is provided almost no time to work on any of it.

I hope you find something that you can do in spite of your impairments - I have yet to meet someone (who worked previously) who was excited to be found disabled.